What is it that makes furniture antique?

The word ‘antique’ has different meanings for different people; for many antique dealers, a piece is classed as antique if it is over 80 years old, while strictly speaking, an item that is more than a century old is classified as an antique. This rule is not set in stone, but technically, an item of furniture that is not yet 100 years old would be classed as vintage.

Furniture Maker’s Signature
One way of identifying a wooden piece of furniture is to look for the manufacturer’s signature, which might come in the form of a label stuck on the bottom or back of the unit. Some antique pieces will have a signature hand carved into the timber, usually in a corner that is concealed from open view, and by asking an experienced antique dealer for his professional opinion on the origins, you can often get an accurate assessment. Looking at online antique dealers, you might find one that has a set of antique chairs for sale, which are made by a particular cabinet maker, as most dealers will have a clear idea of the history of their pieces.
How the Joints are Created
Any wooden antique piece of furniture would have timber joints and the type of joint is a good indicator of its age and authenticity. Anything made prior to the late 17th century would have slightly raised mortice and tenon joints, while 18th century makers preferred to use dovetailed joints, which were in fashion until the mid-19th century. The late 19th century saw machined dovetail joints used for the first time, with anything prior to that period likely to be hand sawn. There is some further reading on how to identify a piece of antique furniture, which is recommended reading for all
novice collectors.
The Wood Finish
One can tell a lot from the type of finish on an antique item of furniture, with shellac being the only clear finish used up until the mid-19th century. If the item is finished with clear lacquer, it is likely made after the mid-19th century, as this was the time when clear lacquers first surfaced. If it is possible to test a small area on the piece with denatured alcohol and if it dissolves, then it is definitely shellac.

The Timber Species
The type of wood used to make a cabinet can tell you a lot about the time of manufacture. Anything made before the start of the 18th century will likely be of oak composition, while mahogany and walnut emerged around that time. Pine has always been a popular timber for furniture making, as was maple and cherry, and in America, pine was the most popular, due to its availability.
If you are unsure about the age or authenticity of any antique item, take a photo and send it to an online antique dealer who can probably give you an accurate diagnosis of its origins. There are many online resources to help you get more acquainted with antique furniture, and all it takes to find such a website is a well worded Google search.
 
*This is a collaborative post.