Stamperia Greyboard: , this 2mm thick greyboard is useful for many kinds of creative projects. Because greyboard is porous, you can use a variety of media on the surface. A layer of white gesso, applied first, will ensure that your colors remain true. Add dimension to a shape by using Texture, Crackle, or Molding Paste. Think in layers... you can stack shapes one on top of the other to make them stand up and off your surface!