Machine cut dovetails were made from the middle of the 1800s onward. Three-ply plywood as we know it today was made in 1905. On turned parts of furniture, such as chair legs, use calipers to take measurements to check for shrinkage.
Antiques will show evidence of use and normal wear and tear.
If you can feel slight, parallel ridges and hollows, the piece was hand planed, probably prior to the mid-19th Century.
Construction techniques can assist you in dating furniture. In the 17th Century, butt and rabbet joints were used.
For example, an olive green recliner with yellow or orange flowers is most likely from the late 1960s to 1970s, as that type of print and color combination hasn't come back into fashion -- yet.Modern upholstered chairs may feature a tag listing both manufacturer and serial number or design name, which can be looked up on the manufacturer's website or on collector websites.Mass-produced chairs from the 19th century to modern times are often stamped with a manufacturer's mark.In the 1800s, this stamp was often placed under the seat or inside a back leg.Sometime during the 18th century, chair makers decided that fluffy armchairs would be more comfortable than the bench-style seats that had been in fashion up to that time.