These Self-Adhesive Polypropylene Mounting Corners by Lineco can be used with light to heavy weight photos and art. Safe and acid-free these corners measure 1.25 inches and will never contact your artwork, keeping it in original and pristine condition. Providing support and allowing for your artwork to expand and contract within its frame, this full view variety minimizes the border required to hide the corner under the window mat. Package includes 250 corners.