Divolo Rabbit Skin Glue

Divolo rabbit skin glue in granules — the protein adhesive for traditional gilding and gesso ground

Protein adhesive obtained from rabbit hides (trimmings), according to the manufacturer. Supplied as solid granules, which the manufacturer describes as yellowish and another written source on the same material describes as hazelnut brown. It swells in cold water and dissolves in a water bath, forming an aqueous solution that, once dry by evaporation, can be redissolved in water. Divolo describes it as very elastic and particularly sought after by gessoists and gilders.

What is it used for?

• Gilding. In water gilding it is used as the size (glue water) for the ground —the Italian colletta— and as the binder for bole preparations.
• Binder for glue tempera (temple à la colle).
• Hardening of artistic scagliola — the technique of imitating marble with gypsum and glue. Not to be confused with plaster of Paris, a fast-setting gypsum.
• Restoration of furniture and inlaid architectural elements using faux-marble technique.
• Cabinetmaking and joinery work.

Why choose Divolo rabbit skin glue?

• It is the binder of the traditional gilding ground. The ground is animal glue plus filler, and the mechanical properties of the whole can be predicted from those of the glue alone (Michalski, 1991).
• Reversible in water: once dry by evaporation, the film can be redissolved in water (manufacturer). Reversibility applies to the glue, not to the intervention: it does not reverse deformations caused in the artwork by heat and pressure.
• Very elastic. The manufacturer describes it as particularly sought after by gessoists and gilders, and states a high adhesive and hardening power.
• Documented ageing. The SPNHC (Society for the Preservation of Natural History Collections, the scientific society that publishes the adhesives guide cited here) records that protein glues age excellently in a stable environment.
• Natural, biodegradable, water-soluble product (manufacturer).

When to use this granulated glue and when something else from our catalogue:

• Divolo ready-to-use gilding bole — already contains rabbit skin glue and solves bole preparation in a single product. Granulated glue is for those who prepare their own bole and control the ratio, filler and concentration.
• Bologna chalk ground and rabbit skin glue (ammannitura) — the ground already formulated. Same criterion: granulated glue is for those who control the ratio and filler.
• Red Armenian bole, water-based gilding size (mixtion) and imitation gold leaf — used alongside the glue, not instead of it: the glue is the binder of the bole preparation.
• Sturgeon isinglass — when a more flexible protein glue is needed (SPNHC).
• Tylose MH 300 P2 — when the determining factor is ambient humidity: an aqueous, non-protein adhesive.
• Wheat starch — when the support is cellulosic: paper and derivatives.
• JunFunori — when matte consolidation is needed, without adding gloss or tension.

Presentation and formats

• Presentation: granules (granulated), in 125 ml · 750 ml · 25 kg.
• The manufacturer states the small formats in millilitres (125 ml and 750 ml): this is the volume of the container, not the weight of the product.

Divolo Firenze is the brand of COBEA S.r.l. (Montepulciano, Siena, Italy).

The limits, spelled out

• Never boil. The manufacturer warns that boiling denatures the proteins. The solution: a water bath, with a documented practical ceiling for the material of 50-60 °C, stirring until fully dissolved.
• High relative humidity. Animal glue loses strength above 75-80% relative humidity (Hackney, 2004).
• Rapid humidity fluctuations. The glue behaves as glassy at low relative humidity and rubbery at high humidity, and the time it takes to move from one state to the other ranges from under an hour at high humidity to many months at low humidity. Hence humidity fluctuations are dangerous only if they are fast (Michalski, 1991). Good humidity is not enough: it must also be stable.
• Microbial attack. Protein glues are highly susceptible to microbial attack, which makes their use in tropical climates inadvisable (SPNHC, Adhesives). The counterpart is in the same source and is stated too: in a stable environment, their ageing is excellent, confirmed by the good condition of historical specimens.
• Water-sensitive artwork. This is an aqueous adhesive: on water-sensitive paint layers or supports, the risk is the water introduced. It should only be used where the support tolerates that input; where it does not, the criterion for choosing an adhesive changes.
• Not for lining paintings on canvas. Glue-paste lining was the historical practice and is documented as damaging: it flattened impasto and permanently erased the trace of the brushstroke (Hackney, 2004). We do not recommend it; today, lining alternatives that do not use animal glue are used.
• Incompatibilities: materials that react with water, and strong oxidisers. This data comes from a safety data sheet for the same family of protein glues, not for this product.
• Shelf life and storage. The manufacturer does not publish a shelf life or storage conditions, either for the dry product or for the prepared solution. If this affects your work, write to us and we will ask Divolo.
• Safety. The manufacturer states that rabbit skin glue “is not hazardous to health and does not irritate the skin.” Divolo does not publish a safety data sheet for this product. The risk of this preparation is thermal, not chemical: the glue is dissolved in a water bath and hot water is used.

References cited on this page: Michalski, S., Crack Mechanisms in Gilding, in Gilded Wood: Conservation and History, Sound View Press, 1991 · Hackney, S., Paintings on Canvas: Lining and Alternatives, Tate Papers 02, 2004 · SPNHC, Adhesives.

Frequently asked questions

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