diff --git a/ChangeLog b/ChangeLog
index 7595660a..f0052df3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,7 @@
 - oop, histnorm was broken by the new vipsstats
 - never use IM ping to get a header, fixes BMP load
 - set @filename for non-vips formats in vips7 compat layer
+- make Xres/Yres double
 
 20/8/11 started 7.27.0
 - version bump for new dev cycle
diff --git a/TODO b/TODO
index 366e729d..a9ac086e 100644
--- a/TODO
+++ b/TODO
@@ -1,24 +1,9 @@
 blocking bugs
 =============
 
-- im_copy_set is broken?
-
-	$ vips im_copy_set babe.jpg x.v 22 2.83 2.83 100 100
-	$ header -a x.v
-	x.v: 1024x768 uchar, 3 bands, srgb VipsImage (0x14e8000)
-	interpretation: 22 - srgb
-	xoffset: 0
-	yoffset: 0
-	xres: 0.000000
-	yres: 0.000000
-
-  xres/yres need to become double (they are float atm)
-
-  the compat stuff and the wrappers in header.c need revising
-
-
 - turning on all debug in object.c causes huge mem use?
 
+  seems to be when making a string for a set of flags?
 
 - none!
 
diff --git a/libvips/conversion/copy.c b/libvips/conversion/copy.c
index d937b9ed..7570ef70 100644
--- a/libvips/conversion/copy.c
+++ b/libvips/conversion/copy.c
@@ -227,7 +227,7 @@ static const char *vips_copy_names[] = {
 	"xres", 	
 	"yres", 
 	"xoffset", 
-	"xoffset",
+	"yoffset",
 	"bands", 
 	"format", 		
 	"coding", 	
diff --git a/libvips/include/vips/header.h b/libvips/include/vips/header.h
index 82f50e58..dcee0143 100644
--- a/libvips/include/vips/header.h
+++ b/libvips/include/vips/header.h
@@ -105,7 +105,7 @@ void vips_image_init_fields( VipsImage *image,
 	int xsize, int ysize, int bands, 
 	VipsBandFormat format, VipsCoding coding, 
 	VipsInterpretation interpretation, 
-	float xres, float yres );
+	double xres, double yres );
 
 int vips_image_copy_fields_array( VipsImage *out, VipsImage *in[] );
 int vips_image_copy_fieldsv( VipsImage *out, VipsImage *in1, ... )
diff --git a/libvips/include/vips/image.h b/libvips/include/vips/image.h
index 601bb22e..3e9ea0c0 100644
--- a/libvips/include/vips/image.h
+++ b/libvips/include/vips/image.h
@@ -263,8 +263,8 @@ typedef struct _VipsImage {
 	VipsBandFormat BandFmt;	/* pixel format */
 	VipsCoding Coding;	/* pixel coding */
 	VipsInterpretation Type;/* pixel interpretation */
-	float Xres;		/* horizontal pixels per millimetre */
-	float Yres;		/* vertical pixels per millimetre */
+	double Xres;		/* horizontal pixels per millimetre */
+	double Yres;		/* vertical pixels per millimetre */
 
 	int Xoffset;		/* image origin hint */
 	int Yoffset;		/* image origin hint */
@@ -294,6 +294,13 @@ typedef struct _VipsImage {
 	 * VipsImage.
 	 */
 
+	/* During vips image read and write we need temporary float-sized
+	 * fields in the struct for staging xres/yres. Don't use these any
+	 * other time.
+	 */
+	float Xres_float;
+	float Yres_float;
+
 	char *mode;		/* mode string passed to _new() */
 	VipsImageType dtype;	/* descriptor type */
 	int fd;         	/* file descriptor */
diff --git a/libvips/iofuncs/header.c b/libvips/iofuncs/header.c
index cd8aee27..219bc9bb 100644
--- a/libvips/iofuncs/header.c
+++ b/libvips/iofuncs/header.c
@@ -153,9 +153,6 @@ static HeaderField int_field[] = {
 	{ "yoffset", G_STRUCT_OFFSET( VipsImage, Yoffset ) }
 };
 
-/* These are actually floats :-( how annoying. We report them as doubles for
- * consistency with the vips_image_*() functions.
- */
 static HeaderField double_field[] = {
 	{ "xres", G_STRUCT_OFFSET( VipsImage, Xres ) },
 	{ "yres", G_STRUCT_OFFSET( VipsImage, Yres ) }
@@ -456,7 +453,7 @@ vips_image_init_fields( VipsImage *image,
 	int xsize, int ysize, int bands, 
 	VipsBandFormat format, VipsCoding coding, 
 	VipsInterpretation interpretation, 
-	float xres, float yres )
+	double xres, double yres )
 {
 	g_object_set( image,
 		"width", xsize,
@@ -554,8 +551,8 @@ vips_image_copy_fields_array( VipsImage *out, VipsImage *in[] )
 	out->Coding = in[0]->Coding;
 	out->Xres = in[0]->Xres;
 	out->Yres = in[0]->Yres;
-	out->Xoffset = 0;
-	out->Yoffset = 0;
+	out->Xoffset = in[0]->Xoffset;
+	out->Yoffset = in[0]->Yoffset;
 
 	/* Count number of images.
 	 */
@@ -750,7 +747,7 @@ vips_image_get( VipsImage *image, const char *field, GValue *value_copy )
 		if( strcmp( field, double_field[i].field ) == 0 ) {
 			g_value_init( value_copy, G_TYPE_DOUBLE );
 			g_value_set_double( value_copy, 
-				G_STRUCT_MEMBER( float, image, 
+				G_STRUCT_MEMBER( double, image, 
 					double_field[i].offset ) );
 			return( 0 );
 		}
@@ -759,7 +756,7 @@ vips_image_get( VipsImage *image, const char *field, GValue *value_copy )
 		if( strcmp( field, old_double_field[i].field ) == 0 ) {
 			g_value_init( value_copy, G_TYPE_DOUBLE );
 			g_value_set_double( value_copy, 
-				G_STRUCT_MEMBER( float, image, 
+				G_STRUCT_MEMBER( double, image, 
 					old_double_field[i].offset ) );
 			return( 0 );
 		}
@@ -1135,13 +1132,13 @@ vips_image_get_double( VipsImage *image, const char *field, double *out )
 
 	for( i = 0; i < VIPS_NUMBER( double_field ); i++ )
 		if( strcmp( field, double_field[i].field ) == 0 ) {
-			*out = G_STRUCT_MEMBER( float, image, 
+			*out = G_STRUCT_MEMBER( double, image, 
 				double_field[i].offset );
 			return( 0 );
 		}
 	for( i = 0; i < VIPS_NUMBER( old_double_field ); i++ )
 		if( strcmp( field, old_double_field[i].field ) == 0 ) {
-			*out = G_STRUCT_MEMBER( float, image, 
+			*out = G_STRUCT_MEMBER( double, image, 
 				old_double_field[i].offset );
 			return( 0 );
 		}
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index e4faeb48..d529b94a 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -925,6 +925,7 @@ vips_object_set_property( GObject *gobject,
 	vips_object_print_name( object );
 	printf( ".%s = %s\n", g_param_spec_get_name( pspec ), str_value );
 	g_free( str_value );
+
 }
 #endif /*DEBUG*/
 
@@ -1372,7 +1373,8 @@ vips_object_class_install_argument( VipsObjectClass *object_class,
 	VipsArgumentClass *argument_class = g_new( VipsArgumentClass, 1 );
 
 #ifdef DEBUG
-	printf( "vips_object_class_install_argument: %s\n", 
+	printf( "vips_object_class_install_argument: %s %s\n", 
+		g_type_name( G_TYPE_FROM_CLASS( object_class ) ),
 		g_param_spec_get_name( pspec ) );
 #endif /*DEBUG*/
 
diff --git a/libvips/iofuncs/vips.c b/libvips/iofuncs/vips.c
index cee70b8a..8c65478b 100644
--- a/libvips/iofuncs/vips.c
+++ b/libvips/iofuncs/vips.c
@@ -255,8 +255,8 @@ static FieldIO fields[] = {
 	{ G_STRUCT_OFFSET( VipsImage, BandFmt ), 4, vips__copy_4byte },
 	{ G_STRUCT_OFFSET( VipsImage, Coding ), 4, vips__copy_4byte },
 	{ G_STRUCT_OFFSET( VipsImage, Type ), 4, vips__copy_4byte },
-	{ G_STRUCT_OFFSET( VipsImage, Xres ), 4, vips__copy_4byte },
-	{ G_STRUCT_OFFSET( VipsImage, Yres ), 4, vips__copy_4byte },
+	{ G_STRUCT_OFFSET( VipsImage, Xres_float ), 4, vips__copy_4byte },
+	{ G_STRUCT_OFFSET( VipsImage, Yres_float ), 4, vips__copy_4byte },
 	{ G_STRUCT_OFFSET( VipsImage, Length ), 4, vips__copy_4byte },
 	{ G_STRUCT_OFFSET( VipsImage, Compression ), 2, vips__copy_2byte },
 	{ G_STRUCT_OFFSET( VipsImage, Level ), 2, vips__copy_2byte },
@@ -304,6 +304,12 @@ vips__read_header_bytes( VipsImage *im, unsigned char *from )
 	 */
 	im->Bbits = vips_format_sizeof( im->BandFmt ) << 3;
 
+	/* We read xres/yres as floats to a staging area, then copy to double
+	 * in the main fields.
+	 */
+	im->Xres = im->Xres_float;
+	im->Yres = im->Yres_float;
+
 	return( 0 );
 }
 
@@ -318,6 +324,12 @@ vips__write_header_bytes( VipsImage *im, unsigned char *to )
 	int i;
 	unsigned char *q;
 
+	/* We set xres/yres as floats in a staging area, then copy those
+	 * smaller values to the file. 
+	 */
+	im->Xres_float = im->Xres;
+	im->Yres_float = im->Yres;
+
 	/* Always write the magic number MSB first.
 	 */
 	vips__copy_4byte( !vips_amiMSBfirst(),