What to look for when buying an Antique Mirror.
A good antique mirror will have certain criterea that makes it an excellent purchase as apposed to just a good or average one.
The first thing to look for with an antque mirror is that the frame is in original condition
When mirror frames were gilded in the 18th/19th centuries they were painted in a red enamel base paint before the gold was applied.
Also but in rare occasions the base paint was yellow enamel. So if the mirror has red showing from under the gold thats fine and if it has lines where the gold panels were applied, thats good also. See first Image.
With early Antique Mirrors the reflective glass is known in the trade as the plate. The plate is the most important part of the mirror.
The reflective effect was achieved by coating the glass with a thin layer of mercury. Mercury gives a crystal clear reflection and acquires a sparkly effect as the mercury breaks down with age. See second Image.
An antique plate is very thick, usually 5-6mm thick.It also has jagged edges where the shape was cut out by nibbling it, by breaking the glass a bit at a time with pliers.A good plate has a little bit of foxing but not so much as to effect the image reflected. See third image
The last thing to check is the back. This ideally should have the pinewood slated back panels original to antique mirror;s however France Italy and Spain, having a more temparate climate have a bigger problem with woodworm than we do and its not unusual to see replacement backs on these pieces. This does effect the value on more expensive pieces but should.nt put you off if the mirror is cheaply priced.
Photos of the back to follow.