A Picture Frame Cardboard Corner Protector  (CPP) as the picture here shows is placed over each corner of photo frames or picture frames to protect them. Artists packing framer works for exhibitions, people moving houses and customers collecting picture frames from their picture framers are prime examples of framed art being moved or transported.  Protection is recommended and necessary when you are carrying or transporting framed art, for instance when moving house or shipping it.  A careless drop, or knock , bump, fall or a slip may damage, spring the corner open, crack the glass  and ...