I hit up Wally World and cleared them out of a few Plano pieces. The organizing has begun. You can of course get as crazy with this as you want, I will probably look for a different material to wrap cars in, maybe a thing black velvet material so it doesn't spring up like the bubble wrap or maybe some of that soft foamy cabinet liner stuff. In the larger cases you may be able to fit the original jewel box liners in the Plano, depends on the size of it. You could even line the bottom of the Plano with the Micro Trains part number card as well so you can see through it and see what it is. I tested Kato unitrack in the Plano 3700 and it fit. Even the tight radius stuff fit, 9.75? Small boxes are 3650 Planos. Big box is 3750. Out the door, I spent $17 for the 3 boxes. Thanks OP for putting this thread up.
I picked up my cigar boxes at yard sales and the guy that bought my old N layouts VERY happily snapped them up. And then I sold the boats and fishing gear and the same happened with the Plano boxes. Amazing how that happens. But I'm watching this here. But, I don't know what a pound is worth.
I'd vote for using the bubble wrap. After using various wraps through the years, it has worked quite well for me. And very easy to obtain. Now and then I also use a soft paper towel, but that does not allow me to see what is inside the wrapping.
DO NOT, and I'll repeat one more time, DO NOT, get that stuff! Way back when I tried that, the "foam" liner interacted with the paint/plastic on my rolling stock and ruined it. Luckily I caught it before it could do major damage but it did leave a very visible mark to this day. The effect was similar to old rubber bands that melted on the things it was wrapped around. After that incident I looked around to see if were any "plastic safe" ones and EVERY manufacturer, including name brands like Rubber Maid, have a fine print warning on the packaging to not have it contact plastic or painted surface for long duration of time (or words to that effect).
Agree with MK on that for sure. Older foam will also start to crumble and can stick to the paint and just make a big mess in general.