Medium density fiberboard, or MDF, is a composite wood product similar to particleboard. It’s made out of wood waste fibers glued together with resin, heat, and pressure. MDF is appropriate for many applications, from cabinetry to molding and its great for countertops because it is smooth, uniform, and won't warp.

MDF has many advantages over plywood, particleboard, or high-density fiberboard. It's very smooth because the wood fibers used in its manufacture are uniform and fine. This makes it have low "tear out," which means that when sawed, the end has a smooth cut instead of a more jagged edge. MDF panels machine very well with carbide tooling and have smooth profiles after the shaping process. MDF also has a mild reaction to moisture, meaning it won't warp or swell in high-humidity applications like a kitchen or bathroom environment.

Builders and fabricators use MDF in many capacities, such as laminate countertops, furniture, shelving, laminate flooring, decorative molding, and doors. They value MDF for its insular qualities in sound and heat. Also, it can be nailed, glued, screwed, stapled, or attached with dowels, making it a truly versatile core material.

Reconstituted, engineered wood products like MDF are often covered with a laminate or veneer sheet. Some people prefer using MDF over regular plywood or lumber products because it has a lower impact on the environment. MDF is solely made from waste products, the leftover scraps that would otherwise be dumped in a landfill. This attraction has helped it gain popularity among homeowners.