Blue Camp Pad
Blue Camping Pads, also commonly referred to as camp pads, Walmart Camp Pads, or blue foam, specifically Ozark Trail brand plain blue camping pads, are a cheap alternative to Polyethylene and a source of passable closed-cell foam commonly used in Belegarth Weapon Construction. It is typically found at Wal-mart, usually costs ~$6/roll, and is roughly 2'x6' in area, making it considerably cheaper than higher-grade closed-cell foams such as Evalite, though it is also significantly less durable.
In 2005, Walmart changed the nature of their camp pads. The new pads are somewhat stiffer, seemingly more durable, and have a rougher texture.
Blue camp pads appear to cost $5.88 (plus tax) at all Wal-marts everywhere.