http://www.google.rs/url?sa=t&rct=j&q=&esrc=s&source=web&cd=...
d. Fish Glue (Russian lsinglas, derived from Sturgeon*).
This has been regarded as the clearest, most desirable gelatin material since the early days of western papermaking.
*sturgeon = jesetra

http://cool.conservation-us.org/coolaic/sg/bpg/annual/v19/bp...
A History of Fish Glue as an Artist's Material: Applications in Paper and Parchment Artifacts
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This article presents a brief historical overview of fish glue as an artist's material applied to paper and parchment artifacts. Artists and craftsmen have appropriated this natural glue since antiquity. Artists have used this material in the preparation of binding media and adhesives, the source for which was a commonly available fish protein. Scientific publications and practical recipe books refer to the use of animal and fish glues in the making and restoring of objects, icons, paintings, illuminated parchment manuscripts, and other artifacts.
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Glue can be extracted from fish by heating the skin or bones in water. The purest form of fish glue, made from the membrane of the air bladder (swim bladder) of certain species of fish such as the sturgeon, is also called isinglass (fig. 1). Isinglass can be produced from various species of fish using diverse manufacturing processes. Depending on the manufacture, the purity of isinglass can vary. Historic sources do not always specify which part of the fish was used to make the glue.

http://en.wikipedia.org/wiki/Isinglass
Isinglass is also used to help repair parchment. 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 °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 that area which has been pre-wet 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.

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Note added at 1 hr (2014-04-18 08:13:32 GMT)
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Evo još jedne mogunosti:
http://www.naturalpigments.com/russian-sturgeon-glue-isingla...
Sturgeon Glue (Isinglass)
Russian Sturgeon Glue (Isinglass) from dried sturgeon bladders of the highest quality, blood and rust free. Our sturgeon glue is the same used by Russian art restorers. Sturgeon glue has higher adhesion and lower visosity than comparable animal glue, such as gelatin or rabbit skin glue.

Isinglass is also used to help repair parchment and paintings. Pieces of the best Russian isinglass are soaked overnight to soften and swell the dried material. Next, it is heated slowly in a bain marie (double boiler) at 45� 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 or wood panels, isinglass can be applied directly to that area which has been pre-wet 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. Here isinglass is similar to parchment 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 heated with a few drops of glycerin or honey. This adhesive is advantageous in situations where minimal use of water is desired for the parchment or painting as the isinglass can be reactivated with an ethanol-water mixture. It also has a greater adhesive strength than many other adhesives used for repair. (Quandt, 1996)

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Note added at 22 hrs (2014-04-19 05:46:06 GMT)
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Wikipedija, stranica na HR koja odgovara stranici na EN za isinglass:
http://hr.wikipedia.org/wiki/Riblje_tutkalo
Riblje tutkalo
Riblje tutkalo je tutkalo dobiveno od sušenih ribljih mjehura. To je vrsta kolagena, a najčešće je korišten za bistrenje piva i vina, te u prehrani. Također daje kvalitetno prirodno ljepilo koje se koristi u konzervaciji umjetnina, prije svega pergamenta. Korišteno je i u starim fotografskim tehnikama te u zlatarstvu (za razne kitove i ljepila). Najkvalitetnije se vrste dobivaju u Rusiji a polazna sirovina su plivaći mjehuri jesetre.

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Note added at 23 hrs (2014-04-19 06:24:34 GMT)
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http://knjizara-rasko.com/cms/index.php?file=slikarski-mater...
Slikarski Materijal
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Zecije tutkalo 100gr. 200gr. 1kg., riblje tutkalo

http://www.scribd.com/doc/24619973/11/Tutkalo
SLIKARSTVO Tehnologija i Tehnike Slikanja
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Riblje tutkalo (lat. ichtyocolla) je osušeni mjehur nekih vrsta riba (jesetre). Poznat je astrahanski riblji mjehur. U nabubrenom stanju se otapa u alkoholu pa se koristi za pripremu fiksativa. Zbog visoke cijene koriste ga samo restauratori.

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Note added at 1 day11 mins (2014-04-19 07:11:51 GMT)
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http://cool.conservation-us.org/coolaic/sg/bpg/annual/v08/bp...
The American Institute for Conservation
Potential Applications of Isinglass Adhesive for Paper Conservation
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Fish glue is an adhesive prepared from the waste products of fish such as the head, skin, and bones. Isinglass is defined as a superior fish gelatin product, produced from the swim bladders of certain species of fish; the quality of the isinglass depends on the chosen species of fish, the manufacturing process, and additives. Because isinglass has been used in Russia for centuries, methods of its manufacture were developed to produce an extremely pure product suitable for conservation. The best grade of isinglass produced today is Russian isinglass, which is prepared from sevrüga and assëtr (English "sturgeon").

Tako da prema prethodno navedenoj definiciji u obzir dolazi i "Russian isinglass" - koji će se od ponuđenih prevoda koristiti zavisi od konteksta, tj. od objašnjenja koje je tačno tutkalo u pitanju.