How to Identify the Best Furniture Materials
Good, well-made furniture is easy to identify, if you know what you're looking for. If you don't know the hallmarks of good furniture, this article will give you a short introduction to this complex topic. I don't expect you to click away an expert, but I do hope to give you the tools to recognize quality, and ask the right questions about a given piece.
What's Inside Counts
Excellent furniture can be made out of any material, from plywood to walnut burl to bubinga to Masonite. The important thing is to understand the characteristics of the most common materials, so you can tell whether a given piece of furniture uses that material appropriately, or in such a way that the material and surrounding structure are prone to failure. Here is an overview of materials and their characteristics, including a few commonly seen - but inappropriate - uses in furniture:
- Solid soft woods (pine, fir, etc...) - solid soft wood is an excellent building material and can be used almost anywhere. Like any solid wood, soft woods expand and contract with humidity, especially across the grain. Because of this, any joint that includes a soft wood member must allow for seasonal movement. Any piece of furniture that "traps" solid wood boards inside a frame or other structure, without allowing for movement, will eventually buckle, deform, or come apart.
- Solid hardwoods (maple, oak, mahogany etc...) - like soft woods, solid hardwood is an excellent material for furniture. There is a large number of species on the market, and some species cost the same as pine and fir. Hardwoods expand and contract with the seasons, and have the same design requirements as soft woods (see above, soft woods).
- Veneer - A veneer is a thin slice of material, used for covering a substrate material such as plywood or MDF. Most furniture uses hardwood veneers; some furniture uses plastic veneers. Veneer is an honest material valued for its economy and ability to bend, as well as its large size and well-matched sections. Veneer is sometimes used to hide staples, screws, or other fasteners from view, in order to give the appearance of more sophisticated construction. Eventually the staples and screw heads start to show as bumps under the veneer.
- Plywood - Plywood is made of two or more "plies" of veneer, glued together. The quality of the veneers, and what they are made of, determines the price and the dimensional stability of the plywood. Plywood doesn't move seasonally, like solid wood does, because each ply is laid down 90 degrees to the ply below, creating a criss-cross pattern of wood grain, restraining movement in each ply. It is a good substrate for veneer. Plywood is difficult to join with fasteners because the mix of wood and glue doesn't hold screws over the long term. If furniture is made with plywood and fasteners, check that none of the screwed-together joints are relying on the screw's threads to support any weight or force. All-plywood furniture is prone to racking (when a rectangular piece of furniture starts to look more like a parallelogram).
- MDF (medium density fiberboard) - MDF is flat, smooth, and cheap, making it an excellent choice as a substrate for veneer or paint. MDF has little strength in any orientation. It can work as a table top, but only if it's well supported underneath, or else it will sag eventually. MDF is also easy to dent, and tends to fray, so exposed corners of MDF will eventually peel apart and turn blunt, usually shedding finish in the process. Too much inexpensive furniture is made with MDF without a protective edging of hard wood or other dent-resistant material.
- Finger-jointed boards (FJ boards) - FJ boards are long boards made up of much shorter pieces, which are glued end-to-end with something called a finger joint. The short pieces (or "cutoffs") are scraps from furniture making with long, solid wood boards. Long, wide boards of real wood get more rare every day, so expect to see more FJ boards in the future. One place you might see FJ boards is in futons or shelving, where long, wide boards are part of the design, but the price has to be kept low. Theoretically, glue is stronger than wood, so FJ boards should be as strong (or stronger) than solid wood. But this is not true in practice. I have seen a lot of broken futon rails, and they all broke at a finger joint. FJ boards should not be used in weight-bearing applications. They are appropriate as edge-banding around MDF or plywood panels.