Tools: Pen case

My partner gifted me with a MUJI case some time ago. The brand lists it as a case for glasses and small articles. I tested using it for my glasses—which did not convince me—and ended up repurposing the translucid case to carry my pens and my water brush. (Right now, it contains a 0.38 MUJI pen, 005 and 03 Micron Sakura pens, and a Pentel watercolor brush whose cap I had to trim with a knife cutter to fit in the case.) The case fits in the side pocket of my Fjällräven Kånken backpack, and it's convenient to place my pens on top of a flat surface as I sketch.