The Print File FoldMats 35mm format in 4x5 Mat are Heavyweight 20 inches paperboard and features quick and easy to load or change sleeved transparencies with no damage to image or mount. It gives excellent finished appearance, both front and back. These are completely reusable without damage to mat or image and repositionable adhesive covers one side of mount and lasts indefinitely, never becomes permanent. Position sleeved transparency anywhere on mat, ReTac™ holds it in place. No cutting or measuring necessary.