Which finishing technique involves applying a liquid to enhance color and protection?

Staining is a finishing technique specifically designed to enhance the color of wood while also providing some level of protection. It consists of a pigmented liquid that penetrates the wood fibers, allowing the natural grain to show through while altering the wood's color to achieve the desired aesthetic. The pigments in the stain help to enrich the appearance of the wood, making it more visually appealing.

In addition to coloring, many stains offer some degree of protection from moisture and UV damage, although this protection may not be as robust as that provided by other finishing methods such as varnishing. This makes staining an essential initial step in many finishing processes, especially when a specific color tone is sought before applying additional protective finishes.

Other options involved in the finishing process serve different purposes. For instance, varnishing is primarily focused on providing a durable protective coating rather than enhancing color. Sanding prepares the surface, smoothing it out before applying any finish, while sealing typically refers to a process that prevents moisture intrusion but may not involve any color enhancement.