I have a bunch of Ikea Ribba picture frames that gape. By this I mean - it's meant to be a rectangle, but each edge buckles slightly so that the whole frame takes on a rounded look. The print that slips out because the little black bendy clips lose their grip on the print. I attach some photos to show what I mean.
Is there a way to fix this? Maybe involving clips/strings that hold the two opposite edges taut? It feels wasteful to throw them away. Please help me save them from the dump!