Alvin Sketch Board Value Pack includes Masonite 23-1/2 x 26 inch Sketch Board with Nylon Portfolio - This set includes a rigid masonite sketch board and a durable nylon portfolio to carry it in. Roomy enough for all your project materials. Board is 4mm thick and features extra firm spring clips to hold paper or pads firmly in place. The giant rubber band keeps the paper secure when sketching outdoors. The sketch board is 23-1/2 inches by 26 inches which will accomodate 18 inch by 24 inch pads and sheets of paper or smaller.