The Dot Line Digital Color Balance Cards provide you with a reference for acquiring accurate color temperature within a particular lighting scenario. These cards are spectrally neutral and are made of a special material that will not warp even if moistened. If the material is stained you can easily wash it off with soap and water. Scratches can also be lightly polished to restore the card's original finish. These cards are universally dyed and can be used on either side. Measuring 8 x 10" in size, these flexible cards offer greater durability than standard cardboard gray cards. These cards come in a reusable clamshell package of 3 cards: one each white, gray, and black.