Small stacking shelves ideally suited for the small plastic parts boxes you might find a selection of passives shipped in from an online retailer.

Base shelf forms bottom of stack.

Each shelf gives 42mm of clearance above the one beneath.

Designed to be strong and also fairly lightweight. Each shelf uses about 100g.

The first version was 125g and when printed with PLA+ I could stand on it, so I pared down the design to be a little lighter. It is still overkill.

Load from the shelf above is distributed directly into the column support below, so many can be stacked without sacrificing much strength. I haven't printed enough of them to test an upper limit yet ;-)

The base is essential to the strength, otherwise the failure mode is the legs splaying out spread-eagle and the deck suffering stress fractures orthogonal to the cross-bracing. Again, given the intended loads it is probably overkill, so omitting the base, lopping off the centering pins and placing rubber stick-on feet is sufficient to obviate lateral motion of the legs if loads are only going to be a few pounds.