A framer that is worth his weight in gold should be conversant with conservation framing methods, like knowing the difference between Museum mount board and Conservation Mount card and when or not to use them. They will need to know how to make sure a valuable work of art is protected from environmental damage, such as light, humidity and acid.
They will need to know when to make a stretcher with cross bars and when to use 3 mm or 5 mm glass. Depending on the size of the artwork, they will need to be able to advise when the weight of glass and backing will put too much strain on a slender molding choice.
They should be able to carry out complex framing requirements. There are of course certain limitations when to framing possibilities and they tend to all be children of size! If your picture is extra large, even extra large glass might not be a possible to use. Remember raw materials are produced in certain sizes and however much you might want your picture behind glass this might not be possible.
It is no good dealing with a framer who does not know his Picasso’s from his Shane Clark’s, whoever he is! You don’t want the framer looking after your valuable work of art when they are unaware of its value. Any framer good framer will have insurance to cover the storage of valuable artworks, but if in doubt it is best to ask.
The easiest way to test if your framer is good or not is to let them lead you. If they are confident with the language of visual things, if they say things like, that colour is too cool, or overpowering, or make observations about the artwork, or ask you where it will hang, you probably are at the right place to have your artwork framed.
The good news when Cambridge is concerned is that the framers there are are up to the job. There was an exceptional picture framers, Frameworks, which was located along mill road. Unfortunately John Caldwell who was the main framer closed shop after 25 years in the business and a local framing gem is no longer. Many local artists still get him to do their frames on an appointment only basis, but the general public have had to look elsewhere!
Cambridge is lucky that among the framing businesses are many ex art school framers with years of experience so you should find the right person for your framing order!