loademwell, the foam (available at hobby and arts supply stores; I got mine at a garage sale years ago) is about 1/2 inch thick. Lining a coffee can with it makes a nice thing to tumble clean cases in to lube them. I put half a dozen or so drops of my case lube on it then dump in enough cases to make it half full.
It's soft enough to let a .308 Win. case fall into it while tumbling in the can and let the case lube get on the case. After several minutes of tumbling, the amount of lube on all the cases is very uniform; both across all the cases as well as all over the case itself. All the cases have the same lubricity as they start into the full length sizing die. A bunch of full length sized cases' headspace has a spread of less than 2 thousandths of an inch.
Here's a picture showing both the cleaning and lubing cans and their liners.
On the left is the 1/8 thick black closed cell foam liner that goes in the can next to it. The black round liner goes in the end of the can. After my tumbling media's put in, these liners prevent the metal can from scratching the cases. And it makes for much, much quieter tumbling cases to clean them inside and out.
On the right's the 1/2 inch thick beige colored open cell foam liner that goes into the lubing can. There's a blue rubber round piece that goes in before the foam so the cases won't get scratched by the can on its bottom as well as quiet it down.
The top covers are not shown.
PS: I get a lot of comments on the bright colored square hard foam pads on my shop floor, but they do keep things in good shape when I drop them on it. Much better than the concrete below them.