diff --git a/ChangeLog b/ChangeLog
index 06716c46..91c1741b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -22,6 +22,9 @@
 - added vips_image_write(), old one becomes vips_image_write_to_file()
 - jpeg read/write copies over XMP data
 - handle offset correctly in separable convolutions (thanks Nicolas)
+- macros for class arg boilerplate
+- class arg order set by new 'priority' param
+- VipsExtend enum added
 
 12/9/11 started 7.26.4
 - fallback vips_init() 
diff --git a/TODO b/TODO
index e006ab92..e4cd3136 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,55 @@
+- embed args are in the wrong order
+
+	$ vips embed
+	vips_embed_class_init
+	VipsEmbed (embed), embed an image in a larger image
+	   embed input type x y width height out
+	where:
+	   input :: VipsImage (input)
+	   type :: gint (input)
+	   x :: gint (input)
+	   y :: gint (input)
+	   width :: gint (input)
+	   height :: gint (input)
+	   out :: VipsImage (output)
+
+  how can we fix this?
+
+  need to give an extra arg to vips_object_class_install_argument() to 
+  specify 'argument priority' ... show args in priority order
+
+
+
+- try some macros for arg specification
+
+	pspec = g_param_spec_int( "y", "Y",
+		_( "Top edge of input in output" ),
+		0, 1000000, 0,
+		G_PARAM_READWRITE );
+	g_object_class_install_property( gobject_class, PROP_Y, pspec );
+	vips_object_class_install_argument( vobject_class, pspec,
+		VIPS_ARGUMENT_REQUIRED_INPUT, 
+		G_STRUCT_OFFSET( VipsEmbed, y ) );
+
+  could become
+
+	VIPS_ARG_INT( class, "y", "Y",
+		_( "Top edge of input in output" ),
+		0, 1000000, 0,
+		VIPS_ARGUMENT_REQUIRED_INPUT, 
+		G_STRUCT_OFFSET( VipsEmbed, y ) );
+
+  could get rid of PROP_ enums as well
+
+
+  doing binary.c next
+
+
+
+- make 'type' field to embed an enum?
+
+
+
 - vips_object_set_argument_from_string() needs more arg types
 
   must be some way to make this more automatic
diff --git a/libvips/arithmetic/arithmetic.c b/libvips/arithmetic/arithmetic.c
index bed9992f..2ccb7712 100644
--- a/libvips/arithmetic/arithmetic.c
+++ b/libvips/arithmetic/arithmetic.c
@@ -53,15 +53,6 @@
 
 #include "arithmetic.h"
 
-/* Properties.
- */
-enum {
-	PROP_OUTPUT = 1,
-	PROP_BOOLTEST = 2,
-	PROP_IMTEST = 3,
-	PROP_LAST
-}; 
-
 G_DEFINE_ABSTRACT_TYPE( VipsArithmetic, vips_arithmetic, VIPS_TYPE_OPERATION );
 
 static int
@@ -96,8 +87,6 @@ vips_arithmetic_class_init( VipsArithmeticClass *class )
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -105,33 +94,22 @@ vips_arithmetic_class_init( VipsArithmeticClass *class )
 	vobject_class->description = _( "arithmetic operations" );
 	vobject_class->build = vips_arithmetic_build;
 
-	pspec = g_param_spec_object( "out", "Output", 
+	VIPS_ARG_IMAGE( class, "out", 1, 
+		_( "Output" ), 
 		_( "Output image" ),
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_OUTPUT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
 		G_STRUCT_OFFSET( VipsArithmetic, output ) );
 
-	pspec = g_param_spec_boolean( "booltest", "Bool test", 
+	VIPS_ARG_BOOL( class, "booltest", 2, 
+		_( "Bool test" ), 
 		_( "Test optional boolean argument" ),
-		FALSE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_BOOLTEST, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsArithmetic, booltest ) );
+		G_STRUCT_OFFSET( VipsArithmetic, booltest ),
+		FALSE );
 
-	pspec = g_param_spec_object( "imtest", "Image test", 
+	VIPS_ARG_IMAGE( class, "imtest", 3, 
+		_( "Image test" ), 
 		_( "Test optional image argument" ),
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_IMTEST, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_OPTIONAL_INPUT, 
 		G_STRUCT_OFFSET( VipsArithmetic, imtest ) );
 }
diff --git a/libvips/arithmetic/avg.c b/libvips/arithmetic/avg.c
index beddd718..c860839b 100644
--- a/libvips/arithmetic/avg.c
+++ b/libvips/arithmetic/avg.c
@@ -86,13 +86,6 @@
  * See also: im_stats(), im_bandmean(), im_deviate(), im_rank()
  */
 
-/* Properties.
- */
-enum {
-	PROP_OUTPUT = 1,
-	PROP_LAST
-}; 
-
 typedef struct _VipsAvg {
 	VipsStatistic parent_instance;
 
@@ -228,8 +221,6 @@ vips_avg_class_init( VipsAvgClass *class )
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
 	VipsStatisticClass *sclass = VIPS_STATISTIC_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -241,17 +232,12 @@ vips_avg_class_init( VipsAvgClass *class )
 	sclass->scan = vips_avg_scan;
 	sclass->stop = vips_avg_stop;
 
-	pspec = g_param_spec_double( "out", "Output", 
+	VIPS_ARG_DOUBLE( class, "out", 2, 
+		_( "Output" ), 
 		_( "Output value" ),
-		-G_MAXDOUBLE,
-		G_MAXDOUBLE,
-		0.0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_OUTPUT, pspec );
-	vips_object_class_install_argument( object_class, pspec,
-		VIPS_ARGUMENT_REQUIRED_OUTPUT | VIPS_ARGUMENT_APPEND, 
-		G_STRUCT_OFFSET( VipsAvg, avg ) );
+		VIPS_ARGUMENT_REQUIRED_OUTPUT,
+		G_STRUCT_OFFSET( VipsAvg, avg ),
+		-G_MAXDOUBLE, G_MAXDOUBLE, 0.0 );
 }
 
 static void
diff --git a/libvips/arithmetic/binary.c b/libvips/arithmetic/binary.c
index dcd1b058..5cddaaa8 100644
--- a/libvips/arithmetic/binary.c
+++ b/libvips/arithmetic/binary.c
@@ -50,14 +50,6 @@
 #include "arithmetic.h"
 #include "binary.h"
 
-/* Properties.
- */
-enum {
-	PROP_LEFT = 1,
-	PROP_RIGHT,
-	PROP_LAST
-}; 
-
 G_DEFINE_ABSTRACT_TYPE( VipsBinary, vips_binary, VIPS_TYPE_ARITHMETIC );
 
 /* Save a bit of typing.
@@ -348,8 +340,6 @@ vips_binary_class_init( VipsBinaryClass *class )
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -359,23 +349,15 @@ vips_binary_class_init( VipsBinaryClass *class )
 
 	/* Create properties.
 	 */
-	pspec = g_param_spec_object( "right", 
-		"Right", "Right-hand image argument",
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_RIGHT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
+	VIPS_ARG_IMAGE( class, "right", 1,
+		_( "Right" ), 
+		_( "Right-hand image argument" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsBinary, right ) );
 
-	pspec = g_param_spec_object( "left", 
-		"Left", "Left-hand image argument",
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_LEFT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
+	VIPS_ARG_IMAGE( class, "left", 2, 
+		_( "Left" ), 
+		_( "Left-hand image argument" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsBinary, left ) );
 }
diff --git a/libvips/arithmetic/min.c b/libvips/arithmetic/min.c
index 7fef11f4..9fec8012 100644
--- a/libvips/arithmetic/min.c
+++ b/libvips/arithmetic/min.c
@@ -83,15 +83,6 @@
  * See also: #VipsAvg, im_stats(), im_bandmean(), im_deviate(), im_rank()
  */
 
-/* Properties.
- */
-enum {
-	PROP_OUTPUT = 1,
-	PROP_X,			/* Position of minimum */
-	PROP_Y,
-	PROP_LAST
-}; 
-
 typedef struct _VipsMin {
 	VipsStatistic parent_instance;
 
@@ -291,8 +282,6 @@ vips_min_class_init( VipsMinClass *class )
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
 	VipsStatisticClass *sclass = VIPS_STATISTIC_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -304,37 +293,26 @@ vips_min_class_init( VipsMinClass *class )
 	sclass->scan = vips_min_scan;
 	sclass->stop = vips_min_stop;
 
-	pspec = g_param_spec_double( "out", "Output", 
+	VIPS_ARG_DOUBLE( class, "out", 1, 
+		_( "Output" ), 
 		_( "Output value" ),
-		-G_MAXDOUBLE,
-		G_MAXDOUBLE,
-		0.0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_OUTPUT, pspec );
-	vips_object_class_install_argument( object_class, pspec,
-		VIPS_ARGUMENT_REQUIRED_OUTPUT | VIPS_ARGUMENT_APPEND, 
-		G_STRUCT_OFFSET( VipsMin, min ) );
+		VIPS_ARGUMENT_REQUIRED_OUTPUT,
+		G_STRUCT_OFFSET( VipsMin, min ),
+		-G_MAXDOUBLE, G_MAXDOUBLE, 0.0 );
 
-	pspec = g_param_spec_int( "x", "x",
+	VIPS_ARG_INT( class, "x", 2, 
+		_( "x" ), 
 		_( "Horizontal position of minimum" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_X, pspec );
-	vips_object_class_install_argument( object_class, pspec,
 		VIPS_ARGUMENT_OPTIONAL_OUTPUT,
-		G_STRUCT_OFFSET( VipsMin, x ) );
+		G_STRUCT_OFFSET( VipsMin, x ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_int( "y", "y",
+	VIPS_ARG_INT( class, "y", 2, 
+		_( "y" ), 
 		_( "Vertical position of minimum" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_Y, pspec );
-	vips_object_class_install_argument( object_class, pspec,
 		VIPS_ARGUMENT_OPTIONAL_OUTPUT,
-		G_STRUCT_OFFSET( VipsMin, y ) );
+		G_STRUCT_OFFSET( VipsMin, y ),
+		0, 1000000, 0 );
 }
 
 static void
diff --git a/libvips/arithmetic/statistic.c b/libvips/arithmetic/statistic.c
index 6acb6bcd..d0e77ef4 100644
--- a/libvips/arithmetic/statistic.c
+++ b/libvips/arithmetic/statistic.c
@@ -52,13 +52,6 @@
 
 #include "statistic.h"
 
-/* Properties.
- */
-enum {
-	PROP_INPUT = 1,
-	PROP_LAST
-}; 
-
 G_DEFINE_ABSTRACT_TYPE( VipsStatistic, vips_statistic, VIPS_TYPE_OPERATION );
 
 static void *
@@ -147,8 +140,6 @@ vips_statistic_class_init( VipsStatisticClass *class )
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -156,14 +147,10 @@ vips_statistic_class_init( VipsStatisticClass *class )
 	vobject_class->description = _( "VIPS statistic operations" );
 	vobject_class->build = vips_statistic_build;
 
-	pspec = g_param_spec_object( "in", "Input", 
+	VIPS_ARG_IMAGE( class, "in", 1, 
+		_( "Input" ), 
 		_( "Input image" ),
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_INPUT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_REQUIRED_INPUT, 
+		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsStatistic, input ) );
 }
 
diff --git a/libvips/conversion/Makefile.am b/libvips/conversion/Makefile.am
index 37e537f5..1c4722c6 100644
--- a/libvips/conversion/Makefile.am
+++ b/libvips/conversion/Makefile.am
@@ -4,6 +4,7 @@ libconversion_la_SOURCES = \
 	conversion.c \
 	conversion.h \
 	copy.c \
+	embed.c \
 	conver_dispatch.c \
 	im_black.c \
 	im_c2amph.c \
diff --git a/libvips/conversion/conversion.c b/libvips/conversion/conversion.c
index 4c5e2d5f..0924d0fc 100644
--- a/libvips/conversion/conversion.c
+++ b/libvips/conversion/conversion.c
@@ -50,13 +50,6 @@
 
 #include "conversion.h"
 
-/* Properties.
- */
-enum {
-	PROP_OUTPUT = 1,
-	PROP_LAST
-}; 
-
 G_DEFINE_ABSTRACT_TYPE( VipsConversion, vips_conversion, VIPS_TYPE_OPERATION );
 
 static int
@@ -84,8 +77,6 @@ vips_conversion_class_init( VipsConversionClass *class )
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
@@ -93,13 +84,9 @@ vips_conversion_class_init( VipsConversionClass *class )
 	vobject_class->description = _( "conversion operations" );
 	vobject_class->build = vips_conversion_build;
 
-	pspec = g_param_spec_object( "out", "Output", 
+	VIPS_ARG_IMAGE( class, "out", 1, 
+		_( "Output" ), 
 		_( "Output image" ),
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_OUTPUT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
 		G_STRUCT_OFFSET( VipsConversion, output ) );
 }
@@ -116,7 +103,9 @@ void
 vips_conversion_operation_init( void )
 {
 	extern GType vips_copy_get_type( void ); 
+	extern GType vips_embed_get_type( void ); 
 
 	vips_copy_get_type();
+	vips_embed_get_type();
 }
 
diff --git a/libvips/conversion/copy.c b/libvips/conversion/copy.c
index fb13797b..5d9a3685 100644
--- a/libvips/conversion/copy.c
+++ b/libvips/conversion/copy.c
@@ -74,8 +74,8 @@
  */
 
 /*
- */
 #define VIPS_DEBUG
+ */
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -108,24 +108,6 @@
  * Returns: 0 on success, -1 on error.
  */
 
-/* Properties.
- */
-enum {
-	PROP_INPUT = 1,
-	PROP_SWAP,
-	PROP_WIDTH,
-	PROP_HEIGHT,
-	PROP_BANDS,
-	PROP_FORMAT,
-	PROP_CODING,
-	PROP_INTERPRETATION,
-	PROP_XRES,
-	PROP_YRES,
-	PROP_XOFFSET,
-	PROP_YOFFSET,
-	PROP_LAST
-}; 
-
 typedef struct _VipsCopy {
 	VipsConversion parent_instance;
 
@@ -344,8 +326,6 @@ vips_copy_class_init( VipsCopyClass *class )
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	VIPS_DEBUG_MSG( "vips_copy_class_init\n" );
 
 	gobject_class->set_property = vips_object_set_property;
@@ -355,116 +335,88 @@ vips_copy_class_init( VipsCopyClass *class )
 	vobject_class->description = _( "copy an image" );
 	vobject_class->build = vips_copy_build;
 
-	pspec = g_param_spec_object( "input", 
-		"Input", "Input image argument",
-		VIPS_TYPE_IMAGE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_INPUT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
+	VIPS_ARG_IMAGE( class, "in", 1, 
+		_( "Input" ), 
+		_( "Input image" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsCopy, input ) );
 
-	pspec = g_param_spec_boolean( "swap", "Swap",
+	VIPS_ARG_BOOL( class, "swap", 2, 
+		_( "Swap" ), 
 		_( "Swap bytes in image between little and big-endian" ),
-		FALSE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_SWAP, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, swap ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, swap ),
+		FALSE );
 
-	pspec = g_param_spec_int( "width", "Width",
+	VIPS_ARG_INT( class, "width", 2, 
+		_( "Width" ), 
 		_( "Image width in pixels" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_WIDTH, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, width ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, width ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_int( "height", "Height",
+	VIPS_ARG_INT( class, "height", 3, 
+		_( "Height" ), 
 		_( "Image height in pixels" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_HEIGHT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, height ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, height ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_int( "bands", "Bands",
+	VIPS_ARG_INT( class, "bands", 4, 
+		_( "Bands" ), 
 		_( "Number of bands in image" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_BANDS, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, bands ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, bands ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_enum( "format", "Format",
+	VIPS_ARG_ENUM( class, "format", 5, 
+		_( "Format" ), 
 		_( "Pixel format in image" ),
-		VIPS_TYPE_BAND_FORMAT, VIPS_FORMAT_UCHAR, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_FORMAT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, format ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, format ),
+		VIPS_TYPE_BAND_FORMAT, VIPS_FORMAT_UCHAR ); 
 
-	pspec = g_param_spec_enum( "coding", "Coding",
+	VIPS_ARG_ENUM( class, "coding", 6, 
+		_( "Coding" ), 
 		_( "Pixel coding" ),
-		VIPS_TYPE_CODING, VIPS_CODING_NONE, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_CODING, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, coding ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, coding ),
+		VIPS_TYPE_CODING, VIPS_CODING_NONE ); 
 
-	pspec = g_param_spec_enum( "interpretation", "Interpretation",
+	VIPS_ARG_ENUM( class, "interpretation", 7, 
+		_( "Interpretation" ), 
 		_( "Pixel interpretation" ),
-		VIPS_TYPE_INTERPRETATION, VIPS_INTERPRETATION_MULTIBAND, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_INTERPRETATION, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, interpretation ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, interpretation ),
+		VIPS_TYPE_INTERPRETATION, VIPS_INTERPRETATION_MULTIBAND ); 
 
-	pspec = g_param_spec_double( "xres", "XRes",
+	VIPS_ARG_DOUBLE( class, "xres", 8, 
+		_( "Xres" ), 
 		_( "Horizontal resolution in pixels/mm" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_XRES, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, xres ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, xres ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_double( "yres", "YRes",
+	VIPS_ARG_DOUBLE( class, "yres", 9, 
+		_( "Yres" ), 
 		_( "Vertical resolution in pixels/mm" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_YRES, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, yres ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, yres ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_int( "xoffset", "XOffset",
+	VIPS_ARG_INT( class, "xoffset", 10, 
+		_( "Xoffset" ), 
 		_( "Horizontal offset of origin" ),
-		-10000000, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_XOFFSET, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, xoffset ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, xoffset ),
+		-1000000, 1000000, 0 );
 
-	pspec = g_param_spec_int( "yoffset", "YOffset",
+	VIPS_ARG_INT( class, "yoffset", 11, 
+		_( "Yoffset" ), 
 		_( "Vertical offset of origin" ),
-		-10000000, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_YOFFSET, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_OPTIONAL_INPUT, 
-		G_STRUCT_OFFSET( VipsCopy, yoffset ) );
-
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsCopy, yoffset ),
+		-1000000, 1000000, 0 );
 }
 
 static void
diff --git a/libvips/conversion/embed.c b/libvips/conversion/embed.c
new file mode 100644
index 00000000..00431db0
--- /dev/null
+++ b/libvips/conversion/embed.c
@@ -0,0 +1,617 @@
+/* im_embed
+ *
+ * Author: J. Cupitt
+ * Written on: 21/2/95
+ * Modified on: 
+ * 6/4/04
+ *	- added extend pixels from edge mode
+ *	- sets Xoffset / Yoffset to x / y
+ * 15/4/04 
+ *	- added replicate and mirror modes
+ * 4/3/05
+ *	- added solid white mode
+ * 4/1/07
+ * 	- degenerate to im_copy() for 0/0/w/h
+ * 1/8/07
+ * 	- more general ... x and y can be negative
+ * 24/3/09
+ * 	- added IM_CODING_RAD support
+ * 5/11/09
+ * 	- gtkdoc
+ * 27/1/10
+ * 	- use im_region_paint()
+ * 	- cleanups
+ * 15/10/11
+ * 	- rewrite as a class
+ */
+
+/*
+
+    This file is part of VIPS.
+    
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+/*
+ */
+#define VIPS_DEBUG
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /*HAVE_CONFIG_H*/
+#include <vips/intl.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include <vips/vips.h>
+#include <vips/internal.h>
+#include <vips/debug.h>
+
+#include "conversion.h"
+
+/**
+ * VipsEmbed:
+ * @in: input image
+ * @out: output image
+ * @type: how to generate the edge pixels
+ * @x: place @in at this x position in @out
+ * @y: place @in at this y position in @out
+ * @width: @out should be this many pixels across
+ * @height: @out should be this many pixels down
+ *
+ * The opposite of im_extract(): embed an image within a larger image. @type
+ * controls what appears in the new pels, see #VipsExtend. 
+ *
+ * See also: im_extract_area(), im_insert().
+ * 
+ * Returns: 0 on success, -1 on error.
+ */
+
+typedef struct _VipsEmbed {
+	VipsConversion parent_instance;
+
+	/* The input image.
+	 */
+	VipsImage *input;
+
+	VipsExtend type;
+	int x;
+	int y;
+	int width;
+	int height;
+
+	/* Geometry calculations. 
+	 */
+	Rect rout;		/* Whole output area */
+	Rect rsub;		/* Rect occupied by image */
+
+	/* The 8 border pieces. The 4 borders strictly up/down/left/right of
+	 * the main image, and the 4 corner pieces.
+	 */
+	Rect border[8];
+} VipsEmbed;
+
+typedef VipsConversionClass VipsEmbedClass;
+
+G_DEFINE_TYPE( VipsEmbed, vips_embed, VIPS_TYPE_CONVERSION );
+
+/* r is the bit we are trying to paint, guaranteed to be entirely within
+ * border area i. Set out to be the edge of the image we need to paint the
+ * pixels in r.
+ */
+static void
+vips_embed_find_edge( VipsEmbed *embed, VipsRect *r, int i, VipsRect *out )
+{
+	/* Expand the border by 1 pixel, intersect with the image area, and we
+	 * get the edge. Usually too much though: eg. we could make the entire
+	 * right edge.
+	 */
+	*out = embed->border[i];
+	vips_rect_marginadjust( out, 1 );
+	vips_rect_intersectrect( out, &embed->rsub, out );
+
+	/* Usually too much though: eg. we could make the entire
+	 * right edge. If we're strictly up/down/left/right of the image, we
+	 * can trim.
+	 */
+	if( i == 0 || i == 2 ) {
+		VipsRect extend;
+
+		/* Above or below.
+		 */
+		extend = *r;
+		extend.top = 0;
+		extend.height = embed->height;
+		vips_rect_intersectrect( out, &extend, out );
+	}
+	if( i == 1 || i == 3 ) {
+		VipsRect extend;
+
+		/* Left or right.
+		 */
+		extend = *r;
+		extend.left = 0;
+		extend.width = embed->width;
+		vips_rect_intersectrect( out, &extend, out );
+	}
+}
+
+/* Copy a single pixel sideways into a line of pixels.
+ */
+static void
+vips_embed_copy_pixel( VipsEmbed *embed, PEL *q, PEL *p, int n )
+{
+	const int bs = VIPS_IMAGE_SIZEOF_PEL( embed->input );
+
+	int x, b;
+
+	for( x = 0; x < n; x++ )
+		for( b = 0; b < bs; b++ )
+			*q++ = p[b];
+}
+
+/* Paint r of region or. It's a border area, lying entirely within 
+ * embed->border[i]. p points to the top-left source pixel to fill with. 
+ * plsk is the line stride.
+ */
+static void
+vips_embed_paint_edge( VipsEmbed *embed, 
+	VipsRegion *or, int i, VipsRect *r, PEL *p, int plsk )
+{
+	const int bs = VIPS_IMAGE_SIZEOF_PEL( embed->input );
+
+	VipsRect todo;
+	PEL *q;
+	int y;
+
+	/* Pixels left to paint.
+	 */
+	todo = *r;
+
+	/* Corner pieces ... copy the single pixel to paint the top line of
+	 * todo, then use the line copier below to paint the rest of it.
+	 */
+	if( i > 3 ) {
+		q = (PEL *) VIPS_REGION_ADDR( or, todo.left, todo.top );
+		vips_embed_copy_pixel( embed, q, p, todo.width );
+
+		p = q;
+		todo.top += 1;
+		todo.height -= 1;
+	}
+
+	if( i == 1 || i == 3 ) {
+		/* Vertical line of pixels to copy.
+		 */
+		for( y = 0; y < todo.height; y++ ) {
+			q = (PEL *) VIPS_REGION_ADDR( or, 
+				todo.left, todo.top + y );
+			vips_embed_copy_pixel( embed, q, p, todo.width );
+			p += plsk;
+		}
+	}
+	else {
+		/* Horizontal line of pixels to copy.
+		 */
+		for( y = 0; y < todo.height; y++ ) {
+			q = (PEL *) VIPS_REGION_ADDR( or, 
+				todo.left, todo.top + y );
+			memcpy( q, p, bs * todo.width );
+		}
+	}
+}
+
+static int
+vips_embed_gen( VipsRegion *or, void *seq, void *a, void *b, gboolean *stop )
+{
+	VipsRegion *ir = (VipsRegion *) seq;
+	VipsEmbed *embed = (VipsEmbed *) b;
+	VipsRect *r = &or->valid;
+
+	Rect ovl;
+	int i;
+	PEL *p;
+	int plsk;
+
+	/* Entirely within the input image? Generate the subimage and copy
+	 * pointers.
+	 */
+	if( vips_rect_includesrect( &embed->rsub, r ) ) {
+		VipsRect need;
+
+		need = *r;
+		need.left -= embed->x;
+		need.top -= embed->y;
+		if( vips_region_prepare( ir, &need ) ||
+			vips_region_region( or, ir, r, need.left, need.top ) )
+			return( -1 );
+
+		return( 0 );
+	}
+
+	/* Does any of the input image appear in the area we have been asked 
+	 * to make? Paste it in.
+	 */
+	vips_rect_intersectrect( r, &embed->rsub, &ovl );
+	if( !vips_rect_isempty( &ovl ) ) {
+		/* Paint the bits coming from the input image.
+		 */
+		ovl.left -= embed->x;
+		ovl.top -= embed->y;
+		if( vips_region_prepare_to( ir, or, &ovl, 
+			ovl.left + embed->x, ovl.top + embed->y ) )
+			return( -1 );
+		ovl.left += embed->x;
+		ovl.top += embed->y;
+	}
+
+	switch( embed->type ) {
+	case 0:
+	case 4:
+		/* Paint the borders a solid value.
+		 */
+		for( i = 0; i < 8; i++ )
+			vips_region_paint( or, &embed->border[i], 
+				embed->type == 0 ? 0 : 255 );
+		break;
+
+	case 1:
+		/* Extend the borders.
+		 */
+		for( i = 0; i < 8; i++ ) {
+			VipsRect todo;
+			VipsRect edge;
+
+			vips_rect_intersectrect( r, &embed->border[i], &todo );
+			if( !vips_rect_isempty( &todo ) ) {
+				vips_embed_find_edge( embed, &todo, i, &edge );
+
+				/* Did we paint any of the input image? If we
+				 * did, we can fetch the edge pixels from
+				 * that.
+				 */
+				if( !vips_rect_isempty( &ovl ) ) {
+					p = (PEL *) VIPS_REGION_ADDR( or, 
+						edge.left, edge.top );
+					plsk = VIPS_REGION_LSKIP( or );
+				}
+				else {
+					/* No pixels painted ... fetch
+					 * directly from the input image.
+					 */
+					edge.left -= embed->x;
+					edge.top -= embed->y;
+					if( vips_region_prepare( ir, &edge ) )
+						return( -1 );
+					p = (PEL *) VIPS_REGION_ADDR( ir,
+						 edge.left, edge.top );
+					plsk = VIPS_REGION_LSKIP( ir );
+				}
+
+				vips_embed_paint_edge( embed, 
+					or, i, &todo, p, plsk );
+			}
+		}
+
+		break;
+
+	default:	
+		g_assert( 0 );
+	}
+
+	return( 0 );
+}
+
+static int
+vips_embed_build( VipsObject *object )
+{
+	VipsConversion *conversion = VIPS_CONVERSION( object );
+	VipsEmbed *embed = (VipsEmbed *) object;
+
+	VipsRect want;
+
+	if( VIPS_OBJECT_CLASS( vips_embed_parent_class )->build( object ) )
+		return( -1 );
+
+	if( vips_image_pio_input( embed->input ) || 
+		vips_image_pio_output( conversion->output ) )
+		return( -1 );
+	if( embed->type < 0 || embed->type > 4 ) {
+		vips_error( "VipsEmbed", "%s", _( "unknown type" ) );
+		return( -1 );
+	}
+
+	/* nip can generate this quite often ... just copy.
+	 */
+	if( embed->x == 0 && 
+		embed->y == 0 && 
+		embed->width == embed->input->Xsize && 
+		embed->height == embed->input->Ysize )
+		return( vips_image_write( embed->input, conversion->output ) );
+
+	switch( embed->type ) {
+	case 2:
+{
+		/* Clock arithmetic: we want negative x/y to wrap around
+		 * nicely.
+		 */
+		const int nx = embed->x < 0 ?
+			-embed->x % embed->input->Xsize : 
+			embed->input->Xsize - embed->x % embed->input->Xsize;
+		const int ny = embed->y < 0 ?
+			-embed->y % embed->input->Ysize : 
+			embed->input->Ysize - embed->y % embed->input->Ysize;
+
+		VipsImage *t[1];
+
+		if( im_open_local_array( conversion->output, 
+			t, 1, "embed-type2", "p" ) ||
+			im_replicate( embed->input, t[0], 
+				embed->width / embed->input->Xsize + 2, 
+				embed->height / embed->input->Ysize + 2 ) ||
+			im_extract_area( t[0], conversion->output, 
+				nx, ny, embed->width, embed->height ) )
+			return( -1 );
+}
+		break;
+
+	case 3:
+{
+		/* As case 2, but the tiles are twice the size because of
+		 * mirroring.
+		 */
+		const int w2 = embed->input->Xsize * 2;
+		const int h2 = embed->input->Ysize * 2;
+
+		const int nx = embed->x < 0 ? 
+			-embed->x % w2 : w2 - embed->x % w2;
+		const int ny = embed->y < 0 ? 
+			-embed->y % h2 : h2 - embed->y % h2;
+
+		VipsImage *t[7];
+
+		if( im_open_local_array( conversion->output, 
+			t, 7, "embed-type3", "p" ) ||
+			/* Cache the edges of in, since we may well be reusing
+			 * them repeatedly. Will only help for tiny borders
+			 * (up to 20 pixels?), but that's our typical case
+			 * with im_conv() etc.
+			im_cache( in, t[0], IM__TILE_WIDTH, IM__TILE_HEIGHT,
+				3 * (in->Xsize / IM__TILE_WIDTH + 1) +
+				3 * (in->Ysize / IM__TILE_HEIGHT + 1) ) ||
+			 */
+
+			/* 
+
+				FIXME ... alternatively, don't cache, hmm,
+				need to time this for typical cases
+
+			 */
+			im_copy( embed->input, t[0] ) ||
+			
+			/* Make a 2x2 mirror tile.
+			 */
+			im_fliphor( t[0], t[1] ) ||
+			im_lrjoin( t[0], t[1], t[2] ) ||
+			im_flipver( t[2], t[3] ) ||
+			im_tbjoin( t[2], t[3], t[4] ) ||
+
+			/* Repeat, then cut out the centre.
+			 */
+			im_replicate( t[4], t[5], 
+				embed->width / t[4]->Xsize + 2, 
+				embed->height / t[4]->Ysize + 2 ) ||
+			im_extract_area( t[5], t[6], nx, ny, 
+				embed->width, embed->height ) ||
+
+			/* Overwrite the centre with the input, much faster
+			 * for centre pixels.
+			 */
+			im_insert_noexpand( t[6], embed->input, 
+				conversion->output, embed->x, embed->y ) )
+				return( -1 );
+}
+		break;
+
+	case 0:
+	case 1:
+	case 4:
+		if( vips_image_copy_fields( conversion->output, embed->input ) )
+			return( -1 );
+
+		conversion->output->Xsize = embed->width;
+		conversion->output->Ysize = embed->height;
+
+		vips_demand_hint( conversion->output, 
+			VIPS_DEMAND_STYLE_SMALLTILE, embed->input, NULL );
+
+		/* Whole output area.
+		 */
+		embed->rout.left = 0;
+		embed->rout.top = 0;
+		embed->rout.width = conversion->output->Xsize;
+		embed->rout.height = conversion->output->Ysize;
+
+		/* Rect occupied by image (can be clipped to nothing).
+		 */
+		want.left = embed->x;
+		want.top = embed->y;
+		want.width = embed->input->Xsize;
+		want.height = embed->input->Ysize;
+		im_rect_intersectrect( &want, &embed->rout, &embed->rsub );
+
+		/* FIXME ... actually, it can't. embed_find_edge() will fail 
+		 * if rsub is empty. Make this more general at some point 
+		 * and remove this test.
+		 */
+		if( vips_rect_isempty( &embed->rsub ) ) {
+			vips_error( "VipsEmbed", "%s", _( "bad dimensions" ) );
+			return( -1 );
+		}
+
+		/* Edge rects of new pixels ... top, right, bottom, left. Order
+		 * important. Can be empty.
+		 */
+		embed->border[0].left = embed->rsub.left;
+		embed->border[0].top = 0;
+		embed->border[0].width = embed->rsub.width;
+		embed->border[0].height = embed->rsub.top;
+
+		embed->border[1].left = VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[1].top = embed->rsub.top;
+		embed->border[1].width = conversion->output->Xsize - 
+			VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[1].height = embed->rsub.height;
+
+		embed->border[2].left = embed->rsub.left;	
+		embed->border[2].top = VIPS_RECT_BOTTOM( &embed->rsub );
+		embed->border[2].width = embed->rsub.width;
+		embed->border[2].height = conversion->output->Ysize - 
+			VIPS_RECT_BOTTOM( &embed->rsub );
+
+		embed->border[3].left = 0;	
+		embed->border[3].top = embed->rsub.top;
+		embed->border[3].width = embed->rsub.left;
+		embed->border[3].height = embed->rsub.height;
+
+		/* Corner rects. Top-left, top-right, bottom-right, 
+		 * bottom-left. Order important.
+		 */
+		embed->border[4].left = 0;
+		embed->border[4].top = 0;
+		embed->border[4].width = embed->rsub.left;
+		embed->border[4].height = embed->rsub.top;
+
+		embed->border[5].left = VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[5].top = 0;
+		embed->border[5].width = conversion->output->Xsize - 
+			VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[5].height = embed->rsub.top;
+
+		embed->border[6].left = VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[6].top = VIPS_RECT_BOTTOM( &embed->rsub );
+		embed->border[6].width = conversion->output->Xsize - 
+			VIPS_RECT_RIGHT( &embed->rsub );
+		embed->border[6].height = conversion->output->Ysize - 
+			VIPS_RECT_BOTTOM( &embed->rsub );
+
+		embed->border[7].left = 0;
+		embed->border[7].top = VIPS_RECT_BOTTOM( &embed->rsub );
+		embed->border[7].width = embed->rsub.left;
+		embed->border[7].height = conversion->output->Ysize - 
+			VIPS_RECT_BOTTOM( &embed->rsub );
+
+		if( vips_image_generate( conversion->output,
+			vips_start_one, vips_embed_gen, vips_stop_one, 
+			embed->input, embed ) )
+			return( -1 );
+
+		break;
+
+	default:
+		g_assert( 0 );
+	}
+
+	return( 0 );
+}
+
+static void
+vips_embed_class_init( VipsEmbedClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
+
+	VIPS_DEBUG_MSG( "vips_embed_class_init\n" );
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	vobject_class->nickname = "embed";
+	vobject_class->description = _( "embed an image in a larger image" );
+	vobject_class->build = vips_embed_build;
+
+	VIPS_ARG_IMAGE( class, "in", -1, 
+		_( "Input" ), 
+		_( "Input image" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, input ) );
+
+	VIPS_ARG_INT( class, "width", 2, 
+		_( "Width" ), 
+		_( "Image width in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, width ),
+		0, 1000000, 0 );
+
+	VIPS_ARG_INT( class, "height", 3, 
+		_( "Height" ), 
+		_( "Image height in pixels" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, height ),
+		0, 1000000, 0 );
+
+	VIPS_ARG_INT( class, "x", 4, 
+		_( "x" ), 
+		_( "Left edge of input in output" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, x ),
+		-1000000, 1000000, 0 );
+
+	VIPS_ARG_INT( class, "y", 5, 
+		_( "y" ), 
+		_( "Top edge of input in output" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, y ),
+		-1000000, 1000000, 0 );
+
+	VIPS_ARG_ENUM( class, "type", 6, 
+		_( "type" ), 
+		_( "How to generate the extra pixels" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsEmbed, type ),
+		VIPS_TYPE_EXTEND, VIPS_EXTEND_BLACK );
+}
+
+static void
+vips_embed_init( VipsEmbed *embed )
+{
+	/* Init our instance fields.
+	 */
+}
+
+int
+vips_embed( VipsImage *in, VipsImage **out, 
+	int x, int y, int width, int height, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, height );
+	result = vips_call_split( "embed", ap, 
+		in, out, x, y, width, height );
+	va_end( ap );
+
+	return( result );
+}
diff --git a/libvips/deprecated/wrapvips7.c b/libvips/deprecated/wrapvips7.c
index be417820..a4964da2 100644
--- a/libvips/deprecated/wrapvips7.c
+++ b/libvips/deprecated/wrapvips7.c
@@ -775,7 +775,7 @@ vips_wrap7_subclass_class_init( VipsWrap7Class *class )
 				(type->flags & IM_TYPE_OUTPUT) ?
 					VIPS_ARGUMENT_REQUIRED_OUTPUT : 
 					VIPS_ARGUMENT_REQUIRED_INPUT,
-				i );
+				i, i );
 			break;
 
 		default:
diff --git a/libvips/include/vips/Makefile.am b/libvips/include/vips/Makefile.am
index 8226d13e..1f170ac7 100644
--- a/libvips/include/vips/Makefile.am
+++ b/libvips/include/vips/Makefile.am
@@ -57,6 +57,7 @@ EXTRA_DIST = version.h.in internal.h enumtemplate
 # well
 vips_scan_headers = \
 	${top_srcdir}/libvips/include/vips/memory.h \
+	${top_srcdir}/libvips/include/vips/conversion.h \
 	${top_srcdir}/libvips/include/vips/util.h \
 	${top_srcdir}/libvips/include/vips/buf.h \
 	${top_srcdir}/libvips/include/vips/image.h \
diff --git a/libvips/include/vips/conversion.h b/libvips/include/vips/conversion.h
index 6e9c5e04..81401dc2 100644
--- a/libvips/include/vips/conversion.h
+++ b/libvips/include/vips/conversion.h
@@ -37,7 +37,49 @@
 extern "C" {
 #endif /*__cplusplus*/
 
-int vips_copy( VipsImage *in, VipsImage **out, ... );
+/** 
+ * VipsExtend:
+ * @VIPS_EXTEND_BLACK; extend with black (all 0) pixels
+ * @VIPS_EXTEND_COPY; copy the image edges
+ * @VIPS_EXTEND_REPEAT; repeat the whole image
+ * @VIPS_EXTEND_MIRROR; mirror the whole image
+ * @VIPS_EXTEND_WHITE; extend with white (all bits set) pixels
+ *
+ * See vips_embed(), vips_conv(), vips_affine() and so on.
+ *
+ * When the edges of an image are extended, you can specify
+ * how you want the extension done. 
+ *
+ * #VIPS_EXTEND_BLACK --- new pixels are black, ie. all bits are zero. 
+ *
+ * #VIPS_EXTEND_COPY --- each new pixel takes the value of the nearest edge
+ * pixel
+ *
+ * #VIPS_EXTEND_REPEAT --- the image is tiled to fill the new area
+ *
+ * #VIPS_EXTEND_MIRROR --- the image is reflected and tiled to reduce hash
+ * edges
+ *
+ * #VIPS_EXTEND_WHITE --- new pixels are white, ie. all bits are set
+ *
+ * We have to specify the exact value of each enum member since we have to 
+ * keep these frozen for back compat with vips7.
+ *
+ * See also: vips_embed().
+ */
+typedef enum {
+	VIPS_EXTEND_BLACK = 0,
+	VIPS_EXTEND_COPY = 1,
+	VIPS_EXTEND_REPEAT = 2,
+	VIPS_EXTEND_MIRROR = 3,
+	VIPS_EXTEND_WHITE = 4
+} VipsExtend;
+
+int vips_copy( VipsImage *in, VipsImage **out, ... )
+	__attribute__((sentinel));
+int vips_embed( VipsImage *in, VipsImage **out, 
+	int x, int y, int width, int height, ... )
+	__attribute__((sentinel));
 
 
 
diff --git a/libvips/include/vips/enumtypes.h b/libvips/include/vips/enumtypes.h
index 95df929c..6d96d032 100644
--- a/libvips/include/vips/enumtypes.h
+++ b/libvips/include/vips/enumtypes.h
@@ -6,6 +6,9 @@
 
 G_BEGIN_DECLS
 
+/* enumerations from "../../../libvips/include/vips/conversion.h" */
+GType vips_extend_get_type (void) G_GNUC_CONST;
+#define VIPS_TYPE_EXTEND (vips_extend_get_type())
 /* enumerations from "../../../libvips/include/vips/util.h" */
 GType vips_token_get_type (void) G_GNUC_CONST;
 #define VIPS_TYPE_TOKEN (vips_token_get_type())
diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index fe0b0632..c81f9fa3 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -62,23 +62,23 @@ extern "C" {
  * will use the most restrictive of the styles requested by the operations 
  * in the pipeline.
  *
- * VIPS_DEMAND_STYLE_THINSTRIP --- This operation would like to output strips 
+ * #VIPS_DEMAND_STYLE_THINSTRIP --- This operation would like to output strips 
  * the width of the image and a few pels high. This is option suitable for 
  * point-to-point operations, such as those in the arithmetic package.
  *
  * This option is only efficient for cases where each output pel depends 
  * upon the pel in the corresponding position in the input image.
  *
- * VIPS_DEMAND_STYLE_FATSTRIP --- This operation would like to output strips 
+ * #VIPS_DEMAND_STYLE_FATSTRIP --- This operation would like to output strips 
  * the width of the image and as high as possible. This option is suitable 
  * for area operations which do not violently transform coordinates, such 
  * as im_conv(). 
  *
- * VIPS_DEMAND_STYLE_SMALLTILE --- This is the most general demand format.
+ * #VIPS_DEMAND_STYLE_SMALLTILE --- This is the most general demand format.
  * Output is demanded in small (around 100x100 pel) sections. This style works 
  * reasonably efficiently, even for bizzare operations like 45 degree rotate.
  *
- * VIPS_DEMAND_STYLE_ANY --- This image is not being demand-read from a disc 
+ * #VIPS_DEMAND_STYLE_ANY --- This image is not being demand-read from a disc 
  * file (even indirectly) so any demand style is OK. It's used for things like
  * im_black() where the pixels are calculated.
  *
diff --git a/libvips/include/vips/object.h b/libvips/include/vips/object.h
index 5607a0d2..0ccae099 100644
--- a/libvips/include/vips/object.h
+++ b/libvips/include/vips/object.h
@@ -52,7 +52,6 @@ typedef struct _VipsObjectClass VipsObjectClass;
  * @VIPS_ARGUMENT_SET_ONCE: can only be set once
  * @VIPS_ARGUMENT_INPUT: is an input argument (one we depend on)
  * @VIPS_ARGUMENT_OUTPUT: is an output argument (depends on us)
- * @VIPS_ARGUMENT_APPEND: add to end of arg list (default is prepend)
  *
  * Flags we associate with each object argument.
  *
@@ -67,8 +66,7 @@ typedef enum {
 	VIPS_ARGUMENT_CONSTRUCT = 2,
 	VIPS_ARGUMENT_SET_ONCE = 4,
 	VIPS_ARGUMENT_INPUT = 8,
-	VIPS_ARGUMENT_OUTPUT = 16,
-	VIPS_ARGUMENT_APPEND = 32
+	VIPS_ARGUMENT_OUTPUT = 16
 } VipsArgumentFlags;
 
 /* Useful flag combinations. User-visible ones are:
@@ -108,6 +106,96 @@ VIPS_ARGUMENT_OPTIONAL_OUTPUT   Eg. the x pos of the image minimum
 	 VIPS_ARGUMENT_CONSTRUCT | \
 	 VIPS_ARGUMENT_SET_ONCE)
 
+extern int _vips__argument_id;
+
+#define VIPS_ARG_IMAGE( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_object( (NAME), (LONG), (DESC),  \
+		VIPS_TYPE_IMAGE, \
+		G_PARAM_READWRITE ); \
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_BOOL( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
+	VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_boolean( (NAME), (LONG), (DESC), \
+		(VALUE), \
+		G_PARAM_READWRITE ); \
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_DOUBLE( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
+	MIN, MAX, VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_double( (NAME), (LONG), (DESC), \
+		(MIN), (MAX), (VALUE), \
+		G_PARAM_READWRITE );\
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_INT( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
+	MIN, MAX, VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_int( (NAME), (LONG), (DESC), \
+		(MIN), (MAX), (VALUE), \
+		G_PARAM_READWRITE );\
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_ENUM( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
+	TYPE, VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_enum( (NAME), (LONG), (DESC), \
+		(TYPE), (VALUE), \
+		G_PARAM_READWRITE );\
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_STRING( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
+	VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_string( (NAME), (LONG), (DESC), \
+		(VALUE), \
+		G_PARAM_READWRITE ); \
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
+#define VIPS_ARG_POINTER( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_pointer( (NAME), (LONG), (DESC), \
+		G_PARAM_READWRITE ); \
+	g_object_class_install_property( gobject_class,  \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
 /* Keep one of these for every argument.
  */
 typedef struct _VipsArgument {
@@ -126,6 +214,7 @@ typedef struct _VipsArgumentClass {
 	VipsObjectClass *object_class;
 
 	VipsArgumentFlags flags;
+	int priority;		/* Order args by this */
 	guint offset;		/* G_STRUCT_OFFSET of member in object */
 } VipsArgumentClass;
 
@@ -332,8 +421,8 @@ gboolean vips_object_sanity( VipsObject *object );
 
 GType vips_object_get_type( void );
 
-void vips_object_class_install_argument( VipsObjectClass *,
-	GParamSpec *pspec, VipsArgumentFlags flags, guint offset );
+void vips_object_class_install_argument( VipsObjectClass *, GParamSpec *pspec, 
+	VipsArgumentFlags flags, int priority, guint offset );
 int vips_object_set_argument_from_string( VipsObject *object, 
 	const char *name, const char *value );
 gboolean vips_object_get_argument_needs_string( VipsObject *object, 
diff --git a/libvips/iofuncs/Makefile.am b/libvips/iofuncs/Makefile.am
index 4f124be1..bb4ce137 100644
--- a/libvips/iofuncs/Makefile.am
+++ b/libvips/iofuncs/Makefile.am
@@ -41,6 +41,7 @@ INCLUDES = -I${top_srcdir}/libvips/include @VIPS_CFLAGS@ @VIPS_INCLUDES@
 # well
 vips_scan_headers = \
 	${top_srcdir}/libvips/include/vips/memory.h \
+	${top_srcdir}/libvips/include/vips/conversion.h \
 	${top_srcdir}/libvips/include/vips/util.h \
 	${top_srcdir}/libvips/include/vips/buf.h \
 	${top_srcdir}/libvips/include/vips/image.h \
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index c87c2e9f..6f158c5b 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -4,6 +4,27 @@
 /* auto-generated enums for vips introspection */
 
 #include <vips/vips.h>
+/* enumerations from "../../libvips/include/vips/conversion.h" */
+GType
+vips_extend_get_type( void )
+{
+	static GType etype = 0;
+
+	if( etype == 0 ) {
+		static const GEnumValue values[] = {
+			{VIPS_EXTEND_BLACK, "VIPS_EXTEND_BLACK", "black"},
+			{VIPS_EXTEND_COPY, "VIPS_EXTEND_COPY", "copy"},
+			{VIPS_EXTEND_REPEAT, "VIPS_EXTEND_REPEAT", "repeat"},
+			{VIPS_EXTEND_MIRROR, "VIPS_EXTEND_MIRROR", "mirror"},
+			{VIPS_EXTEND_WHITE, "VIPS_EXTEND_WHITE", "white"},
+			{0, NULL, NULL}
+		};
+		
+		etype = g_enum_register_static( "VipsExtend", values );
+	}
+
+	return( etype );
+}
 /* enumerations from "../../libvips/include/vips/util.h" */
 GType
 vips_token_get_type( void )
@@ -158,7 +179,6 @@ vips_argument_flags_get_type( void )
 			{VIPS_ARGUMENT_SET_ONCE, "VIPS_ARGUMENT_SET_ONCE", "set-once"},
 			{VIPS_ARGUMENT_INPUT, "VIPS_ARGUMENT_INPUT", "input"},
 			{VIPS_ARGUMENT_OUTPUT, "VIPS_ARGUMENT_OUTPUT", "output"},
-			{VIPS_ARGUMENT_APPEND, "VIPS_ARGUMENT_APPEND", "append"},
 			{0, NULL, NULL}
 		};
 		
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index bd6e06a0..ceade629 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -143,28 +143,6 @@
  * Returns: The address of pixel (x,y) in the image.
  */
 
-/* Properties.
- */
-enum {
-	PROP_WIDTH = 1,
-	PROP_HEIGHT,
-	PROP_BANDS,
-	PROP_FORMAT,
-	PROP_CODING,
-	PROP_INTERPRETATION,
-	PROP_XRES,
-	PROP_YRES,
-	PROP_XOFFSET,
-	PROP_YOFFSET,
-	PROP_FILENAME,
-	PROP_KILL,
-	PROP_MODE,
-	PROP_DEMAND,
-	PROP_SIZEOF_HEADER,
-	PROP_FOREIGN_BUFFER,
-	PROP_LAST
-}; 
-
 /* Our signals. 
  */
 enum {
@@ -938,12 +916,11 @@ vips_image_class_init( VipsImageClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
-	GParamSpec *pspec;
 
 	VIPS_DEBUG_MSG( "vips_image_class_init:\n" );
 
 	/* Pass in a nonsense name for argv0 ... this init world is only here
-	 * for old programs which are missing an vips_init() call. We must
+	 * for old programs which are missing a vips_init() call. We must
 	 * have threads set up before we can process.
 	 */
 	if( vips_init( "vips" ) )
@@ -972,149 +949,114 @@ vips_image_class_init( VipsImageClass *class )
 	/* Create properties.
 	 */
 
-	/* Width / height / bands can be zero for unintialised.
-	 */
-	pspec = g_param_spec_int( "width", "Width",
+	VIPS_ARG_INT( class, "width", 2, 
+		_( "Width" ), 
 		_( "Image width in pixels" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_WIDTH, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Xsize ) );
-	pspec = g_param_spec_int( "height", "Height",
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Xsize ),
+		0, 1000000, 0 );
+
+	VIPS_ARG_INT( class, "height", 3, 
+		_( "Height" ), 
 		_( "Image height in pixels" ),
-		0, 1000000, 0,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_HEIGHT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Ysize ) );
-	pspec = g_param_spec_int( "bands", "Bands",
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Ysize ),
+		0, 1000000, 0 );
+
+	VIPS_ARG_INT( class, "bands", 4, 
+		_( "Bands" ), 
 		_( "Number of bands in image" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_BANDS, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Bands ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Bands ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_enum( "format", "Format",
+	VIPS_ARG_ENUM( class, "format", 5, 
+		_( "Format" ), 
 		_( "Pixel format in image" ),
-		VIPS_TYPE_BAND_FORMAT, VIPS_FORMAT_UCHAR, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_FORMAT, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, BandFmt ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, BandFmt ),
+		VIPS_TYPE_BAND_FORMAT, VIPS_FORMAT_UCHAR ); 
 
-	pspec = g_param_spec_enum( "coding", "Coding",
+	VIPS_ARG_ENUM( class, "coding", 6, 
+		_( "Coding" ), 
 		_( "Pixel coding" ),
-		VIPS_TYPE_CODING, VIPS_CODING_NONE, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_CODING, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Coding ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Coding ),
+		VIPS_TYPE_CODING, VIPS_CODING_NONE ); 
 
-	pspec = g_param_spec_enum( "interpretation", "Interpretation",
+	VIPS_ARG_ENUM( class, "interpretation", 7, 
+		_( "Interpretation" ), 
 		_( "Pixel interpretation" ),
-		VIPS_TYPE_INTERPRETATION, VIPS_INTERPRETATION_MULTIBAND, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_INTERPRETATION, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Type ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Type ),
+		VIPS_TYPE_INTERPRETATION, VIPS_INTERPRETATION_MULTIBAND ); 
 
-	pspec = g_param_spec_double( "xres", "XRes",
+	VIPS_ARG_DOUBLE( class, "xres", 8, 
+		_( "Xres" ), 
 		_( "Horizontal resolution in pixels/mm" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_XRES, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Xres ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Xres ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_double( "yres", "YRes",
+	VIPS_ARG_DOUBLE( class, "yres", 9, 
+		_( "Yres" ), 
 		_( "Vertical resolution in pixels/mm" ),
-		0, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_YRES, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Yres ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Yres ),
+		0, 1000000, 0 );
 
-	pspec = g_param_spec_int( "xoffset", "XOffset",
+	VIPS_ARG_INT( class, "xoffset", 10, 
+		_( "Xoffset" ), 
 		_( "Horizontal offset of origin" ),
-		-10000000, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_XOFFSET, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Xoffset ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Xoffset ),
+		-1000000, 1000000, 0 );
 
-	pspec = g_param_spec_int( "yoffset", "YOffset",
+	VIPS_ARG_INT( class, "yoffset", 11, 
+		_( "Yoffset" ), 
 		_( "Vertical offset of origin" ),
-		-10000000, 1000000, 0, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_YOFFSET, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_SET_ONCE, 
-		G_STRUCT_OFFSET( VipsImage, Yoffset ) );
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsImage, Yoffset ),
+		-1000000, 1000000, 0 );
 
-	pspec = g_param_spec_string( "filename", "Filename",
+	VIPS_ARG_STRING( class, "filename", 12, 
+		_( "Filename" ),
 		_( "Image filename" ),
-		NULL, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_FILENAME, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_CONSTRUCT, 
-		G_STRUCT_OFFSET( VipsImage, filename ) );
+		G_STRUCT_OFFSET( VipsImage, filename ),
+		NULL );
 
-	pspec = g_param_spec_string( "mode", "Mode",
+	VIPS_ARG_STRING( class, "mode", 13, 
+		_( "Mode" ),
 		_( "Open mode" ),
-		"p", 			/* Default to partial */
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_MODE, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_CONSTRUCT, 
-		G_STRUCT_OFFSET( VipsImage, mode ) );
+		G_STRUCT_OFFSET( VipsImage, filename ),
+		"p" );
 
-	pspec = g_param_spec_boolean( "kill", "Kill",
+	VIPS_ARG_BOOL( class, "kill", 14, 
+		_( "Kill" ),
 		_( "Block evaluation on this image" ),
-		FALSE, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_KILL, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_NONE, 
-		G_STRUCT_OFFSET( VipsImage, kill ) );
+		G_STRUCT_OFFSET( VipsImage, kill ),
+		FALSE );
 
-	pspec = g_param_spec_enum( "demand", "Demand",
+	VIPS_ARG_ENUM( class, "demand", 15, 
+		_( "Demand style" ), 
 		_( "Preferred demand style for this image" ),
-		VIPS_TYPE_DEMAND_STYLE, VIPS_DEMAND_STYLE_SMALLTILE,
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, PROP_DEMAND, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
-		VIPS_ARGUMENT_NONE, 
-		G_STRUCT_OFFSET( VipsImage, dhint ) );
+		VIPS_ARGUMENT_NONE,
+		G_STRUCT_OFFSET( VipsImage, dhint ),
+		VIPS_TYPE_DEMAND_STYLE, VIPS_DEMAND_STYLE_SMALLTILE );
 
-	pspec = g_param_spec_int( "sizeof_header", "Size of header",
+	VIPS_ARG_INT( class, "sizeof_header", 16, 
+		_( "Size of header" ), 
 		_( "Offset in bytes from start of file" ),
-		0, 1000000, VIPS_SIZEOF_HEADER, 
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_SIZEOF_HEADER, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
 		VIPS_ARGUMENT_SET_ONCE | VIPS_ARGUMENT_CONSTRUCT, 
-		G_STRUCT_OFFSET( VipsImage, sizeof_header ) );
+		G_STRUCT_OFFSET( VipsImage, sizeof_header ),
+		0, 1000000, VIPS_SIZEOF_HEADER );
 
-	pspec = g_param_spec_pointer( "foreign_buffer", "Foreign buffer",
-		"Pointer to foreign pixels",
-		G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class, 
-		PROP_FOREIGN_BUFFER, pspec );
-	vips_object_class_install_argument( vobject_class, pspec,
+	VIPS_ARG_POINTER( class, "foreign_buffer", 17, 
+		_( "Foreign buffer" ),
+		_( "Pointer to foreign pixels" ),
 		VIPS_ARGUMENT_SET_ONCE | VIPS_ARGUMENT_CONSTRUCT, 
 		G_STRUCT_OFFSET( VipsImage, data ) );
 
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index 96b468a2..2151cd74 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -48,14 +48,6 @@
 #include <vips/internal.h>
 #include <vips/debug.h>
 
-/* Properties.
- */
-enum {
-	PROP_NICKNAME = 1,/* Class properties as object props */
-	PROP_DESCRIPTION,
-	PROP_LAST
-};
-
 /* Our signals. 
  */
 enum {
@@ -72,6 +64,8 @@ static GMutex *vips__object_all_lock = NULL;
 
 static guint vips_object_signals[SIG_LAST] = { 0 };
 
+int _vips__argument_id = 0;
+
 G_DEFINE_ABSTRACT_TYPE( VipsObject, vips_object, G_TYPE_OBJECT );
 
 void
@@ -1058,8 +1052,6 @@ vips_object_class_init( VipsObjectClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 
-	GParamSpec *pspec;
-
 	if( !vips__object_all ) {
 		vips__object_all = g_hash_table_new( 
 			g_direct_hash, g_direct_equal );
@@ -1092,29 +1084,19 @@ vips_object_class_init( VipsObjectClass *class )
 	g_value_register_transform_func( G_TYPE_STRING, G_TYPE_DOUBLE,
 		transform_string_double );
 
-	/* Create properties.
-	 */
-	pspec = g_param_spec_string( "nickname",
+	VIPS_ARG_STRING( class, "nickname", 1, 
 		_( "Nickname" ),
 		_( "Class nickname" ),
-		"",
-		(GParamFlags) G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class,
-		PROP_NICKNAME, pspec );
-	vips_object_class_install_argument( class, pspec,
 		VIPS_ARGUMENT_SET_ONCE,
-		G_STRUCT_OFFSET( VipsObject, nickname ) );
+		G_STRUCT_OFFSET( VipsObject, nickname ), 
+		"" );
 
-	pspec = g_param_spec_string( "description",
+	VIPS_ARG_STRING( class, "description", 2, 
 		_( "Description" ),
 		_( "Class description" ),
-		"",
-		(GParamFlags) G_PARAM_READWRITE );
-	g_object_class_install_property( gobject_class,
-		PROP_DESCRIPTION, pspec );
-	vips_object_class_install_argument( class, pspec,
 		VIPS_ARGUMENT_SET_ONCE,
-		G_STRUCT_OFFSET( VipsObject, description ) );
+		G_STRUCT_OFFSET( VipsObject, description ), 
+		"" );
 
 	vips_object_signals[SIG_PRECLOSE] = g_signal_new( "preclose",
 		G_TYPE_FROM_CLASS( class ),
@@ -1154,11 +1136,20 @@ vips_object_init( VipsObject *object )
 	g_mutex_unlock( vips__object_all_lock );
 }
 
+static gint
+traverse_sort( gconstpointer a, gconstpointer b )
+{
+	VipsArgumentClass *class1 = (VipsArgumentClass *) a;
+	VipsArgumentClass *class2 = (VipsArgumentClass *) b;
+
+	return( class1->priority - class2->priority );
+}
+
 /* Add a vipsargument ... automate some stuff with this.
  */
 void
 vips_object_class_install_argument( VipsObjectClass *object_class,
-	GParamSpec *pspec, VipsArgumentFlags flags, guint offset )
+	GParamSpec *pspec, VipsArgumentFlags flags, int priority, guint offset )
 {
 	VipsArgumentClass *argument_class = g_new( VipsArgumentClass, 1 );
 
@@ -1181,16 +1172,15 @@ vips_object_class_install_argument( VipsObjectClass *object_class,
 	((VipsArgument *) argument_class)->pspec = pspec;
 	argument_class->object_class = object_class;
 	argument_class->flags = flags;
+	argument_class->priority = priority;
 	argument_class->offset = offset;
 
 	vips_argument_table_replace( object_class->argument_table,
 		(VipsArgument *) argument_class );
-	if( flags & VIPS_ARGUMENT_APPEND )
-		object_class->argument_table_traverse = g_slist_append(
-			object_class->argument_table_traverse, argument_class );
-	else
-		object_class->argument_table_traverse = g_slist_prepend(
-			object_class->argument_table_traverse, argument_class );
+	object_class->argument_table_traverse = g_slist_prepend(
+		object_class->argument_table_traverse, argument_class );
+	object_class->argument_table_traverse = g_slist_sort(
+		object_class->argument_table_traverse, traverse_sort );
 }
 
 /* Set a named arg from a string.