PVC. Light micrograph of fibres of PVC, also known as polyvinyl chloride or polychloroethene. PVC is a tough, white material, which softens with the application of a plasticizer. It is manufactured by heating chloroethene either with an inert solvent in the presence of an initiator such as benzoyl peroxide or else under water with potassium persulphate or hydrogen peroxide to initiate the free-radical mechanism. Magnification: x80 at 6x4.5cm size.