PVC is one of thousands of plastics in use today. PVC's technical name is poly vinyl chloride. It is unique among plastics in that it is composed of nearly 60% chloride that stems from rock salt (sodium chloride) and about 40% polymers stemming from natural gas and petrochemicals.

Virgin vinyl is the term applied to vinyl that is extruded for the first time. Regrind is the term given to vinyl that has been extruded, then the parts are ground up into small "pellets" and can be re-extruded. The implication is that "virgin vinyl" is purer or superior to reground vinyl. As a thermo plastic, PVC can be reprocessed, typically, around three times with little degradation to the compound. After that, additional processing "uses up" some of the lubricants and other additives that are used in the extrusion process. Alcor’s frames, sashes and other major window parts are extruded from virgin vinyl.