I am looking to create a bunch of movement trays soon to help encourage me to finally get this solo gaming experiment off the ground. I hate making movement trays. It's tedious. But it's less tedious than dealing with units of individual figures every time you move them, game after game.
My recent switch to multi-bases is a good solution that would help me avoid needing trays... except I still have all of these old single based figures I also want to use. So new movement trays it is.
I don't recall if I published this diagram here before. This is my old method of basing, trays, and transport/storage boxes. All magnetized to avoid damage, and also make it easy to pull out full units of figures at the time of gaming. I used to hate spending a half hour arranging figures into units before a game.
The steel I use is galvanized steel from the hardware store. It's usually with the HVAC duct parts. It can be cut with a pair of snips or robust scissors. I use it in the bottom my my carrying boxes, and used to use it on old movement trays.
But then I discovered "ferrous rubber" or "magnetic receptive rubber." Easier to work with and store. It's available from various sources. I think I first bought some from the Gale Force Nine booth at a convention long ago. But I've discovered I can get that as well as magnetic sheet direct from a local supplier for far less.
My movement trays are cut from either matte-board or chipboard from the art store, or polystyrene sheet, and if I add a"lip" or outer edge, that's either basswood or polystyrene.