This declaration covers SPC rigid core flooring produced by member companies of the Resilient Floor Covering Institute. SPC stands for stone plastic (or polymer) composite and is LVT with a rigid core that is durable and dense due to its high limestone (calcium carbonate) content. SPC rigid core is a multi-layer product with a high performance finish, transparent and print layers, and SPC core. Some products have an optional acoustical underlayment. The print layer includes wood, stone, and other natural types of digital imaging to maximize aesthetic alternatives. In addition to limestone filler, materials in this flooring product category include vinyl (polyvinyl chloride or PVC), pigments, plasticizers, extenders, and stabilizers. See Figure 1. for a cross-section diagram of SPC rigid core flooring.