Tactile Sandpaper Flash Cards - Lowercase Letters Beginning readers and special needs students will benefit from the tactile experience of Tactile Sandpaper Flash Cards from Didax. These 4 1/4-inch by 2 5/8-inch cards are covered with fine yellow sand and help students make the connection between the physical movement of forming letters and the actual letter shapes. The set contains 26 standard lower case letters plus two alternative forms of L and T. These have some signs of use as the sandpaper tends to scratch the others