Last year Core77 forum moderator Timf posted,
The other day one of my students asked me what a self healing cutting mat is made of. I have done a search and only found the mysterious phrase "made of a unique self healing composite material". Does anyone know what they are made of?
None of the respondents (or Google, for that matter) had the answer, and a few pointed out that the "self-healing" description is a bit of marketing spin, to which most of us can attest; the "self-healing" cutting mats I used at school all looked like Federal informants someone had failed to assign guards to.
In response to yesterday's post on cutting mats, a reader named Adam opined that UHMW (Ultra-high-molecular-weight) Polyethylene would be a good substitute. UHMW is a tough, low-friction, largely chemical-resistant thermoplastic often used for industrial-sized food-processing surfaces. It's more abrasion-resistant than carbon steel and is used for pickup truck beds, the bottoms of skis (because gouges can be easily filled and repaired), and if you've ever seen those skateboarding gloves with the plastic bits that downhillers can use to place their hand on asphalt whipping by beneath them, that stuff is UHMW too.
I'm not certain that's what cutting mats are made of, only because UHMW is odorless and every cutting mat I've used had a strong vinyl smell; then again cutting mats are usually three layers, a rigid core bookended by layers of softer stuff, so perhaps the vinyl smell comes from the center layer, and perhaps you can do without it.
In any case, poking around revealed that a company called Modern Plastics sells UHMW-PE in sheets, at prices well below what you'd pay for the cutting mats we mentioned yesterday; a 1/8-inch-thick sheet of 4'x10' goes for $91.40, compared to the $160 you'd shell out for a gridless 4'x10' at DraftingSteals.com.
One caveat: If you're going to order from Modern Plastics, you might want to double up with a buddy, as they have a minimum order policy of $150.00.