This came up in a PM suggestion for wider exposure on another forum, and I had forgotten about the post here. Anyone that has done testing with Red Sea or Hanna checkers will know what a pain safely drying out the cuvettes can be. I've almost broke some a few times from knocking them on a shelf.
Last month I got into the world of 3D printing, but couldn't find anything quite like I had wanted. The closest was for hanging single API cuvettes on a tank, so after some SketchUp work and a few sizing tests, the result is these:
cuvette_holder2 by
Kyl, on Flickr

cuvette_holders by
Kyl, on Flickr
The STL files for both the Hanna and Red Sea versions (along with sizing test prints) are available to download on
Thingiverse. One thing to note is that I'll be revising designs slightly when some more time becomes available. Temporary cap storage while drying will likely be included in a v2, but these currently work quite well for the main goal - securing the cuvettes while they dry out instead of falling and breaking.
Happy printing and reefing!