It is also used as speaker foam due to the high air-flow its structure allows. Note: This foam is dark charcoal. Details. Characteristics: A reticulated, open-pore, flexible, ether-type of polyurethane foam. Characterized by a skeletal structure of strands which provide a constant 97 percent void space and a very high degree of permeability. Custom-Cut Closed Cell Foam. Our versatile closed-cell foam options don’t stop at sheets and pads. Select from the custom shapes below that work best for the job at hand. After clicking your desired shape, enter the dimensions to generate a price quote. For shapes not shown here, click on the Pattern Shape below. 1/8" Thick Density Closed Cell Foam Sold by the Yard 56" Wide. Will cut one continuous piece if more than on yard is ordered. Craft Foam Hi Dense Closed Cell Foam Sheet Upholstery Foam Graphite or White For Auto Interior Panels, Crafts, Speakers, Padding Craft Supplies and other DIY Projects.