MDF (medium-density fiberboard) is inexpensive, durable, and a good choice for many woodworking and carpentry projects. Medium-density fiberboard is the most versatile building material. Because it’s inexpensive and durable, it’s a good choice for practical projects like shelving and storage cabinets. MDF is also great for decorative projects. The smooth surface is perfect for painting, and a router leaves crisp profiles with no splintering, burning or tear-out.
The face of MDF is harder than most woods, but the inner layers are soft. So edges, and especially corners, are easy to crush. That means you have to handle it with more care than lumber or plywood. Also, avoid scratching the face. Light scratches stand out like a sore thumb on the ultra-smooth surface, so you have to sand them out completely before priming.
Keep Away From WaterMDF stands up to moisture about as well as crackers. A few water drops will raise small bumps on the surface. A long soaking will make it swell to twice its original thickness. So MDF is a risky choice for baseboards in entryways and trim near tubs or sinks.