The Framers Forum

Two questions. 1.What is the joint termed on the let in miter and the origin of it? 2. When were keys first introduced in stretcher bars?

Thank you.
Richard

Stretcher bars and wedges go back an extremely long time. Probably for many centuries. I don't suppose that the actual date can even be guessed at.

The joint is called a tapered key joint ( or something to that effect ).
I believe it dates from around the 17th cent when artists began to paint more on canvases instead of wooden panels and could so choose to have their frames made and fitted by cabinet or frame makers.
Before that, pictures surrounded by a frame were mostly devotional and constructed as an 'engaged' object where the painted panel and frame were manufactured as one.
Using this method of joining and holding the mitres closed results in a very strong joint which gives security to all the directions of joint stress.
The stretcher keys used to stretch canvases would obviously date from the same period.

Thank both you for the history. This frame has what appears to be a thin gesso layer underneath the paint. When did they first start this process?

At least 3,000 years ago.

Items removed from the Egypt pyramids were decorated with gold and they used gesso on these items. I don,t know how long ago this was, but at least 3,000 years ago as said by Jerome in the previous post would be a reasonable date for this to be correct.

Yes, gesso has been around for centuries. When artists first noticed that if they mixed ground gypsum or other soft rock dust with some glue, you could make a paste that could be painted over a flat piece of wood and when dry, and if sanded smooth would then make an ideal fresco-like surface on which to paint pretty pictures.
That went on right up to the 14th century as well as artists and carpenters sticking thin sheets of gold onto the gesso surface so as to give the impression of a solid gold construction.
After this time, you had cabinet makers in Holland making picture frames in ebony wood which they happened to have loads of at the time - Dutch trading ships were coming in using it as ballast. This dense wood gives a beautiful smooth surface which when polished, has only a very fine grain structure showing.
As time went on to the 17th cent, other frame makers were producing ebonised frames for popular prints and mezzotint's and whereas most were faced with fruitwood as an alternative to ebony, there were some producers who applied gesso to the base wood first, sanded it back to a smooth finish and then painted on a black varnish so as to make a cheaper version of both the ebony and fruitwood frames.
So, in answer to your question, I would say that gesso underneath paint or black varnish dates from the 17th cent onwards.