Generally duct tape is composed of three layers. A top layer of resilient plastic (vinyl or polyethylene), a bottom layer of rubber-based adhesive and a middle layer of fabric mesh. The tape was formerly manufactured by pressing these three layers together but some manufacturers have developed a single-step process. | Generally duct tape is composed of three layers. A top layer of resilient plastic (vinyl or polyethylene), a bottom layer of rubber-based adhesive and a middle layer of fabric mesh. The tape was formerly manufactured by pressing these three layers together but some manufacturers have developed a single-step process. |