Glazes contain little or no white pigments, allowing the substrate to remain visible. For wood, a distinction is made between thin-layer glazes, which penetrate deeply into the wood, and thick-layer glazes, which form a protective surface film. Thin-layer glazes allow natural wood breathing but require more frequent renewal. Thick-layer glazes provide better UV and moisture protection. On rendered surfaces, lime-cement or mineral glazes create decorative colour effects with a vivid depth appearance. In painting technique, a glaze refers to a transparent colour layer applied over an opaque base coat. Adhesion to wood is determined by the content of film-forming binders such as alkyd resin or acrylate.