Like many others, I needed storage for smaller portions of filament. After trying the “shrink a full size stand” routine I chose to make one of my own. This accommodates a number of mini spools shared on Printables and Thingiverse. The keeper on the open side is 45mm in diameter; the different spools I’ve printed have an inside diameter of around 50mm. The horizontal width behind the keeper is 34.2mm clear. Hindsight shows a little wider horizontal dimension would have been useful. But I usually use the smallest diameter filament spool (150x25 for up to 200g) by DaVinci2000 on Thingiverse as this spool offers options that do not require wider spools. I used 3 diameters, 3 top and bottom layers and 20% infill. Support is required for the spindle. Once completed I used 3 sticky dots on the 3 corners to keep if from sliding on the Lack surface.