To Articap
The blue blocks are made of a very dense ABS plastic.
When I worked as Training Director for a heavy construction company I worked on a project in which the mechanics installed liners in some of the dump trucks. The idea was to prevent wear on the beds of the trucks and so that material would slide out easier when the truck was dumped.
The installation made scrap pieces of this stuff available that were about two feet by four feet in size. It is exactly half an inch thick.
It is a dream to work with. It cuts easily. It is as tough as nails, almost bulletproof. It is strong enough that when I use the press, the alignment stays pretty true.
I put a chunk of this stuff on the top of the workbench I use for my pistols. I can lay a pistol part down and not have to worry about scratching the finish.
I love the stuff. I got a dozen pieces of it. (We did the experiment on 12 trucks) I am not looking forward to the time when I use the last piece of it.