Crescent Select Mat board are made by Crescent Paper Company. They are 4ply boards which make them about 1/16" thick. These mats have a black core and either a white or black top surface. Crescent Select Acid free conservation archival mat boards are safe to use on original fine art. They are safe to come in contact your fine art work. This board meets the conservation standards of the framing industry. It will protect your art and prints while maintaining its beauty with non fading pigment surface colors.