Review on Lineco Archival Polypropylene Mounting Corners - Self Adhesive, Pressure Sensitive, Non-Yellowing, Acid-Free - 1.25 Inches (3,175 Centimeter) - for Mounting Artwork, Photographs, Certificates, Scrapbooking, DIY, Displaying Pictures - Pack of 250 - Clear by Kristen Simpson

These mounting brackets do the job well but are a bit awkward to use. First you need to remove the unused middle part of the corner to fully reveal the rim that will hold your piece. I then found that it was necessary to "open" the two sides of the border to allow the imprint to be inserted. When the cutter clogs the border between the edge and the center, the border "sticks" to the substrate. After these two preparatory steps, it's pretty easy to paste the print into the corner, peel off the backing, and tape the corner in place. Once installed, the angles are great; completely transparent, acid-free and very hard.