Collecting antique furniture is a costly endeavor. You don't want to make any mistakes and buy a misrepresented piece that you thought was worth hundreds of dollars or more.
Signs of Age
Measure a piece of wood furniture. Wood shrinks as it ages by up to 1/8 inch per foot. If the furniture is old, its dimensions will not be uniform - it won't be the same width throughout, and a tabletop will not be completely round.
Run your hand over and shine a flashlight across the surface of the wood to detect hairline cracks and ripples that come with aging.
Look underneath for the inevitable warping and buckling of wood.
Look for wood that is discolored from uneven exposure to light and sun. An old piece of furniture that has stood against a wall for years will show its age with distinct differences in coloring.
Check the wood beneath the hardware. Here, the wood should show even greater contrasts in color.
Look at the screws. Screws made before 1840 had flat, un-tapered heads.
Search for the signs of normal wear and tear and the buildup of dust and grime in the furniture's corners and crevices.
Look at the frame under the upholstery for sets of nail holes from previous upholstery. An aged piece may have seen several changes in fabric.
Use a pocket level on a piece of glass or a mirror. Glass, too, warps with age.
Signs of Newness
Look closely at the various pieces of wood used in the furniture - particularly the edges and feet. Differences between the pieces would indicate that parts have been replaced.
Beware of smooth edges from a power saw in contrast to the ragged edges made by a handsaw.
Distinguish between the older plank-style construction and the more modern tongue-and-groove construction.
Inspect for old or filled nail and screw holes that would have been made when the piece was originally built.
Open drawers and doors and look for screw holes that indicate that the original handles and hinges are gone.
Look at dovetail joints. New dovetails are either machine-made or much narrower than the wide, up-to-3/8-inch dovetails of the 1800s.
Compare all the dovetail joints in the piece. Perfect matching could mean the furniture is newer than advertised. Gross differences would demonstrate that pieces have been replaced.
Check out the surfaces. Uniformity in coloring, texture and smoothness points to newness or refinishing.