Your profile says you're from the US. I got my blocking mats at Costco, actually, but you might also try Home Depot or another big hardware store. They're sometimes sold as padding to make being on your feet in your workshop more comfy.
I'd seen some of those in a hardware/general household goods shop, and thought about them, but they were thinner, only about 1cm thick. I wanted the thicker, more rigid ones, myself, because I only have space to do things like this on my bed! So tonight, I can take the whole thing off and stand it up against a wall, and it'll keep its shape; the thinner ones would bend and distort, I suspect.
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Date: 2009-11-25 06:30 pm (UTC)(no subject)
Date: 2009-11-25 06:38 pm (UTC)(no subject)
Date: 2009-11-25 06:40 pm (UTC)(no subject)
Date: 2009-11-25 06:42 pm (UTC)