I've got a pile of boxes of small parts from Aliexpress. I thought a rack was in order. A search only netted me designs of a fixed number layers, or modular systems for larger boxes than I have. The original design (https://www.printables.com/model/1510250-stackable-rack-for-aliexpress-boxes) is for the 15 segment boxes, all my boxes only have 10 segments, So I had to do a redesign of the very excellent, but too big for me system. The originator also didn't include a top, and I wanted one. So here we are.

2 walls, and 15% infill is more than enough for the weight of the boxes and contents, and you won't need supports.

Note: I had to link the original thing in the summary, because Thingiverse isn't super good at linking stuff from other sites.