Hand-planning the bottom of a chair or drawer. If a seat bottom shows signs of hand-planing, it was probably made before 1810.
Construction Joints the joints between two pieces of wood. 18th-century furniture was often pegged and glued, not nailed. Look for irregularly shaped and spaced dovetails (notches cut in wood so pieces fit together like puzzle pieces). Until the last half of the 19th century, these were cut by hand and shouldn't be perfectly spaced or formed.
Size of Boards Tabletops and backs of dressers, bureaus. These should be built with one solid piece or different pieces of various widths if the piece is truly old. Perfectly sized and spaced boards indicate new construction. Saw Marks On the backs of chests and under tables. Straight saw marks indicate the piece was made before the mid-18th century. Wavy lines (cut with a band saw) show it was made in the mid-18th to 19th century. Look for circular saw patterns in furniture made after that.
Secondary Wood Inside drawers and on dresser backs. The builders of old furniture used less-expensive wood in places where it wouldn't show. No secondary wood is a sure sign of new construction,and any plywood is a dead giveaway.
Original Paint Finish Cracks or dents in painted furniture. If the paint finish is original, exposed wood should appear in any cracks and gouges. If you spy paint down in the cracks and crevices, then it's been painted since the ding occurred.
Antique Glass Mirrors. Antique glass is very thin. Test by placing a coin on edge against the mirror. If the reflection is very close to the coin itself, almost touching it, the glass is old.
Wormholes On the surface of any wood piece. Stick a pin in the hole. If the pin goes straight through, the hole is manufactured. True wormholes are winding paths.
What to look for: Style Reputable dealers Auction Estate sales Wear and tear Furniture shows
