Walter designed a spectacular lightweight easy to print camera filter case way back in 2013. You can find his original version here https://www.thingiverse.com/thing:43781. I've been printing and using these cases for for more than 10 year. I've always had a problem with my magnets falling out though so I've changed his design so that the magnets are now enclosed. You'll need to pause your printer just before the holes close up to insert the magnets. You can find this point on your slicer when slicing.

Also I've added two lines of text to the case so you can label your filters. Note, these are short labels (3-4 characters). As with Walter's design, you'll probably need to edit the OpenScad file to use your exact filter dimensions, magnet sizes, and preferred text. Walter wrote some great code so all the variables you need to edit are nicely at the front of the code and well commented. For my magnets I added 0.15 mm to diameter and 0.12 mm to the height for the opening. I added 1 mm to the filter width and 0.8 mm to the height to get a good size opening.

As Walter mentions in his description, it is super important to orient the magnets correctly so the case stays closed. It's even more important in this design since you can't get the magnets out without breaking the print.