A button image should be the size of an icon: not larger them 256 x 256 pixels. I usually keep it to about 72 x 72 pixels. The only way to do that is save it at that size. I usually use IcoFX (
http://icofx.ro/) to create a button image and IrfanView (
http://www.irfanview.com/) to modify an existing image (both free). v-tools (
http://www.skrol29.com/us/vtools.php) includes a utility that will list all button images contained within Access. Google image search is also a great resource.