GlasPly® Premier is a specially constructed, asphalt-coated, fiber glass ply felt for use in hot applied built-up and modified bitumen roofing systems which is produced by first impregnating a special high strength Johns Manville (JM) fiber glass mat with a quality asphalt. It is treated with a unique liquid parting agent that eliminates sticking when the felt is unrolled. Before the product is wound into rolls, it is imprinted with laying lines on the top surface so the roofing mechanic can install the felt with the proper exposure and provide the correct number of plies.