My little baby is going to turn one next month! I made this onesie for him to wear on the big day. Now big brother wants one with a three on it :). It will be easy enough to do. Just print out a number in the font of your choice and enlarge it as necessary on a copier. Trace the back of the image (the wrong side so the image will be mirrored) onto fusible web. Iron the fusible web onto the wrong side of your fabric, and cut out the number on the lines. Iron the number onto your shirt, then blanket stitch around the edges. Done!