Graphic-quality ID card stock in various shapes and sizes and materials. ID cards come many sizes. The most common sizes are CR79 (3.303" x 2.051"), CR80 (3.375" x 2.125" - same as a credit card), and CR100 (3.88" x 2.63"). The most common size is CR80 and all card printers are designed to print on CR80 size cards.