I used to keep all my Evergreen styrene strips in their original bags, which was pretty sensible as it listed the dimensions of the strips as well as the product number. However, over the years I have acquired a lot of bags of styrene in various sizes and the process of finding what I needed became unmanageable. I came across an amazing solution while searching online, but it really was a bit too large for my needs. Some people like plastic PVC pipe cut down but that leads to a lot of wasted space. Plus, my organizer needs to be mobile so I can bring it to work sessions at friends' houses.
So, I went to Lowes and looked around, and then looked around some more. Here and there, pricing various wooden dowels and trim pieces and boards and pipes. The challenge was making it strong enough to withstand dropping a tool on it (which could happen) while not overbuilding it and causing the budget or space requirements to go up. This is what I came up with. It ain't pretty, but it works.
Most of the square dowels are 1/4" and though they aren't perfectly straight they work well enough. I used wood glue to attach them and put enough on to build up a fillet at the bottom to prevent thin styrene from getting jammed underneath. Occasionally I clamped one of the pieces down at the end but otherwise I just put weights on top and left it at that. If I really cared I could have used some small track nails to hold the dowels while the glue dried but I was afraid of them splitting. For my larger, odd shaped styrene I built an organizer with 1/4" x 1/2" window screen trim. I should have made the slots slightly over 1/2" wide.
The wooden slats across the top help keep the styrene from bouncing around (and out!) and are glued at every joint. Everything was given a spray of dark blue paint to make the styrene visually pop out. I thought I purchased flat blue but it turned out to be gloss, which is probably better because it is more durable in the long run.
Keeping track of what I have and where it is will be problematic. My temporary solution was to write down on an index card what is in every slot. I don't want to assign slots to certain sizes because if I need to move stuff around it will be a hassle. But, I also don't want to reach for my calipers every time I pull a piece. It is a work in progress.
I want to build a "Cradle" of sorts that is just little wider and deeper than the racks I built. That way, I can slide these in it and it will prevent them from shifting and sliding around. But do they work? Yes! I partially dumped one already and most of the stuff stayed in place. Yay!