Editing Isinglass (section)

== Conservation ==

Isinglass is also used as an adhesive to repair [[parchment]], stucco and damage to paintings on canvas. Pieces of the best Russian isinglass are soaked overnight to soften and swell the dried material. Next, it is cooked slowly in a [[double boiler]] at 45&nbsp;°C while being stirred. A small amount of [[gum tragacanth]] dissolved in water is added to the strained isinglass solution to act as an [[emulsifier]].

When repairing paint that is flaking from parchment, isinglass can be applied directly to an area which has been soaked with a small amount of [[ethanol]]. It is typically applied as a very tiny drop that is then guided, with the help of a [[binocular microscope]], under the edges of flaking paint.

It can also be used to coat tissue or [[goldbeater's skin]]. On paintings this can be used as a temporary backing to either canvas patches or filler until dried. Here, isinglass is similar to parchment [[Sizing|size]] and other forms of gelatin, but it is unique in that as a dried film the [[adhesive]] can be reactivated with moisture. For this use, the isinglass is cooked with a few drops of [[glycerin]] or [[honey]].
This adhesive is advantageous in situations where minimal use of water is desired for the parchment as the isinglass can be reactivated with an ethanol-water mixture. It also has a greater adhesive strength than many other adhesives used for parchment repair.<ref>{{cite journal |last=Quandt |first=Abigail B. |date=1996 |title=Recent Developments in the Conservation of Parchment Manuscripts |publisher=The American Institute for Conservation |journal= The Book and Paper Group Annual |s2cid=190456099 |s2cid-access=free |url=https://pdfs.semanticscholar.org/50a8/0ab2039432d9d5326c39ae52f8419142ced2.pdf |archive-url=https://web.archive.org/web/20200212005651/https://pdfs.semanticscholar.org/50a8/0ab2039432d9d5326c39ae52f8419142ced2.pdf |url-status=dead |archive-date=2020-02-12 |access-date=2020-07-21}}</ref>