Because wood shrinks across the grain but not along it, very old furniture may appear to be misshapen. A tabletop that was round when it was made becomes slightly oval with great age. Wooden pegs that jut out just a bit from the surface of a chair leg or cabinet side are also indicators of age-related shrinkage.
The way furniture is put together is an important indicator of age. Early craftsmen used hand-cut mortise-and-tenon joints, dovetail joints and wooden pegs. Hand cut dovetails are wider and cruder than dovetails made with machines starting in the mid-19th century. Nails tell their own story. Rose Head nails were forged individually by blacksmiths in the 1700s. After shaping the nail, the blacksmith placed it in a heading tool and delivered several hammer blows to form the distinctive head. Cut nails were prominent from 1790 to 1890. Sharp-ended wire nails with flat, round heads began to be machine produced around 1880. Staples are hallmarks of 20th-century manufacture.
Different cutting and sanding tools leave distinctive marks on wood and give clues to the era during which a piece of furniture was made. Look for saw marks on unfinished backs and undersides. Straight, irregular marks indicate pre-1830 hand cut wood. Around 1830, sawmills cut wood, leaving straight, even marks. Circular cuts are post 1850. Exposed surfaces of antiques were hand-sanded. They're less smooth and even than machine-sanded surfaces.
Now that you know the difference between a reproduction and an authentic antique, where's the best place to pick one up?