Masking refers to a technique used to protect certain areas of a painting or artwork from receiving paint, allowing artists to create crisp, sharp edges, and preserve white spaces or underlying layers. Golden Artist Colors offers various products that facilitate masking, such as QoR Masking Fluid for watercolor and High Flow Acrylics with masking capabilities. Masking can be achieved using different tools and methods, including applying masking fluids or tapes, and can be used with various mediums, including watercolor, acrylics, and oils. The goal of masking is to control the application of paint and achieve desired visual effects, such as highlights, textures, and layered compositions. (Source IDs: products-930, videos-99)