Black Polypropylene Jewel Cases?

Has anyone ever tried the 3.8mm or 4mm thin Black Polypropylene Jewel Cases made by Linkyo?

I usually store my CD/DVD/BR discs in binders to keep them out of the path of strong light or sunlight. I’ve had a few discs killed by sunlight. But sometimes you just don’t want to have a big heavy binder on the table and I thought that one of these might be a “light tight” alternative for a single disc.

Anyone have any experience with them or something like them?