Water Stains from Old Embroidery?
I have an approx 50 year old large embroidery picture on what appears to be a cotton backing cloth that belonged to my mother. It has been framed as a picture for most of its life by being folded around a piece of plywood with a glass front as per a normal picture.
At some stage it obviously got damp and there are some localised water stains on the backing cloth (outside of the main embroidered area and hence visible). It looks like standard embroidery thread on a cotton cloth backing.
Is there any 'safe' way of removing the water stains before we re-frame it?