Donna Salazar's 3 in. x 4 in. Acrylic Stamping Block 1/4 in. Thick is perfect for Artist Trading Card. This acrylic stamping block fits our unmounted ATC stamps and many other acrylic stamps that will fit on a 3 in. x 4 in. surface. Make sure you purchase the Tack 'N Peel Cling Sheet or the EZ Mount Foam, so you can use it to mount your unmounted red rubber stamps onto and use over and over.