The Dot Line Digital Gray Cards provide you with a reference for acquiring accurate color temperature within a particular lighting scenario. These 18% Digital Gray 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 uniformly 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 2 cards.