Photo Buttons Made from durable metal with a sturdy pin for fastening. Available in 4-inch (at left and below) and 3-inch diameters. Note:   A 4.5-inch photo is used to produce the 4-inch button, so you will have to be careful to use a photo that still looks good after cropping (3.4-inch image used for 3-inch button). Buttons require that your photo have at least 640x640 pixels. Buttons have very accurate color reproduction, but not as accurate as photographic prints.