In my work, I need to store and process paper before they eventually end up in a binder. I couldn't find a tray that I could print that would do the job, so I designed this.

It consists of 4 legs that are glued to 4 corners, and a center piece that holds the legs in place to form an X. There are two "corners" - "left" and "right" - which have cut outs allowing space to slide papers into the tray, and taking them out again. Assembly requires gluing the pieces together.

For additional strength, you could glue two center pieces together like a base and a lid, encapsulating the legs anchor points.