Don't know if many use this material for their platen, but I purchased some canvas backed graphite (HDI) today for $1.72 per YARD. Was told it was very durable, but time will tell. Bad things are you can't order online, you must call, and minimum purchase was 15 yards. (Better prices for bigger quantities.) Just thought it might be useful for anyone using this material. Knifemaker supply companies that I have seen want $4.00 per FOOT.
www.proengcorp.com
www.proengcorp.com