I needed a small stacked shelving for a narrow spot. The commercial “letter trays" are far too large. This can be easily modified in TinkerCAD to add a lip around the edge or a plate area to add a contents sticker. Go wild….. I will add some alternatives later…..

I made mine with PLA+ as i dont plan to put anything heavy on it. However one could use ABS/PETG if required.

I have designed this to use Q-Connect risers ( https://amzn.eu/d/7fejezA ). These are 123mm (4.8") tall and are 5.5mm thick but could be cut down to suit.