Library Bookmark and Receipt Holder

My local library gives a receipt with the due date for their books. I wanted a way to protect it and use it as a bookmark.

I used Claude 4.8 to rapidly iterate through designs to prototype things on the go. I wanted to see how well it could design with some rough sketches and crude measurements. The 4.8 model did great, lower level models struggled. 

The back has a tongue that can clip onto pages. You can either bend the bookmark slightly to flare the clip out onto a page, or heat it up with a lighter and bend it for a permanent setup. 

Slide the receipt over the backing and then slide the front over it, using the dovetail rails on the sides. Mine had a friction fit, but consider a little tape if you notice it sliding around. 

I included the openscad files so that folks can adjust things for their own use. 

 Print both halves face down at .2mm layer height. There is a B variant that can take in a logo for the front of the bookmark. The B variant of the scad file takes in a vector file to stanp your own logo. 

Update 

I made a few revisions (V14) on the back tongue that now has grooves to fold it, making it a much easier clasp for a bookmark, and a top lip to catch on the front panel so that the parts won't slide if they loosen up over time. Print like normal, with both pieces face down and then fold the grooves of the tongue until they feel like a good angle. Enjoy!