Oval bubble glass frames are often advertised for sale on ebay. These are dated from the 1890’s to the 1920’s.
The mouldings vary from the elaborate made from plaster, to the more common timber.
One often seen is called “Tiger Wood”. (not to be confused with the famous golfer!)
The photograph in the frame was called a “Crayon enlargement” and was bowed outwards in a convex shape. This made it fit against the glass which was also made convex. The whole effect was very striking and would have made a talking point in many Edwardian homes.
Crayon enlargements were typically made using a bromide print. They were then bowed over a mould to give the convex shape.The photographic image was underexposed and served as a guide for a final work that looks more like a drawing.
The print was then hand coloured using crayons – hence the name.