Need a guide for card sizes? Me too. Most of the cards I make are A2. But, I have a stash of envelopes that are for various card sizes. So, here's a chart that I created with the measurements for the most commonly used card sizes. A1 3 ½ × 4 ⅞ 3.5” × 4.875” A2 4 ¼ × 5 ½ 4.25” × 5.5” A6 4 ½ × 6 ¼ 4.5” × 6.25” A7 5” × 7” Biz 3 ½ × 2 3.5” × 2 Square 5 ½ × 5 ½ 5.5” × 5.5” ETA: I figured it would be nice to have measurements for the corresponding layers. Here you go: Card Size Card Measurements Layers Measurements A1 3 ½ × 4 ⅞ 3.5” × 4.875” 3 ¼ × 4 ⅝ 3.25” × 4.625” A2 4 ¼ × 5 ½ 4.25” × 5.5” 4 × 5 ¼ 4” × 5.25” A6 4 ½ × 6 ¼ 4.5” × 6.25” 4 ¼ × 6 4.25” × 6” A7 5” × 7” 4 ¾ × 6 ¾ 4.75” × 6.75” Biz 3 ½ × 2 3.5” × 2 3 ¼ × 1 ¾ 3.25” × 1.75” Square 5 ½ × 5 ½ 5.5” × 5.5” 5 ¼ × 5 ¼ 5.25” × 5.25”