One measure of woodworking quality is the type of joinery used. If you look closely at the corners of any piece of furniture, you will see what I mean. Check how the builder decided to hold the edges together. Strength and style should determine what kind of joint is used. While you want a look that enhances the piece, strength is the most important factor. A weak joint inevitably leads to broken furniture.
Nails, screws, or knockdown cam & bolt connectors are common ways of joining wood. But when you look at fine furniture or antiques, you are much more likely to find one of these:
Dado Joint
A dado is a slot cut in a board to receive another board. Deceptively simple but requires care to obtain a tight fit. Dados are commonly used in joining large panels, bookshelves, and cabinets.
Mitered Butt Joint
A butt joint is simply two pieces of wood butted up together. A mitered butt joint has both pieces cut at a 45 degree angle. This gives it a slightly better glue surface and has the esthetic value of not showing any end grain. The disadvantage of this joint is that it isn’t very strong, so you will seldom see it used on larger pieces. It can be enhanced with splines to make it stronger and to create interesting effects.
Box Joint
Box joints are sometimes called finger joints. Lace your fingertips together, and you get a pretty good idea of what it looks like. They are often used for jewelry boxes and keepsake boxes as well as drawers. The extra gluing surfaces make it strong, and the end grain contrast makes a nice, artistic effect.
Dovetail Joint
A dovetail joint is a form of box joint with the fingers locked together by diagonal cuts. It is even stronger than a box joint and has been used by carpenters for thousands of years in high-quality boxes and drawers. Dovetails often provide clues about the quality and age of furniture pieces. Perfect, hand-cut dovetails are the mark of a master craftsman.
