I have designed this case in Fusion 360 to store my 3D filament swatches from jjjlee (https://makerworld.com/en/models/72898).

Initially I printed the big case from there but it did not close properly so I designed my own based on the same idea from the toolkits from iFixit, meaning that the case closes with magnets and you can store the lid under the case itself to save space in your desk, as there are places for magnets on the bottom as well. Stores a total of 80 swatches.

Print in PLA or other material of your choice, no supports are needed even for the text if your printer/material is handling overhangs nicely.

The magnets used are 6x2mm magnets from https://www.amazon.es/dp/B0CNRDSPF8, and the holes are a tight fit but still you can drop a bit of super glue to fix them in place if you like. If you have trouble getting the magnets in, you can tap them gently with a small hammer and a piece of wood in between, so it doesn't mark the parts. Be careful with the magnet polarization before fitting them.