All the parts are laser cut from plywood. This has a slightly rough surface and benefitted from sanding on the faces to smooth things off. The parts lock together well with only a little PVA in the joins being enough to hold them. The centra handle keeps everything inline and stops the trays falling off while you carry them.
24 Humbrol pots are a tight fit into each level. I'm wondering about using them for small tools on the workbench as at 195 by 142mm, there should be space for all those regularly used items that don't make it back into the drawer.
Should you want a taller tray, a 5 tier version is available.
2 layer tray from L-Cut.