These picture mats are made of high quality acid free cardboard Acid Free: These kids art frames are made of high quality acid free cardboard to slow down child’s cherished artwork yellowing and fading Bevel Cut: The kids art frame with ivory core adopts a 45° bevel cut and 1mm thick to increase the layering of the artwork Dimensions: Each art frame will fit for 8.5×11 inches artwork; The display window measures 8×10.5 inches; Total size: 11×14 inches; Frames can show drawing, 2D and 3D artwoks vertically or horizontally For Decoration: The frame is perfect for decorating kids drawings, artworks, children art projects, schoolwork Comes With: You will receive 12 frame black mats, there is also a roll of double-sided tape