Rabbit Skin Glue

 

Rabbit Skin Glue is a refined animal glue size. Traditional uses include: binder in Traditional Gesso, binder for Size Paints and a Size for canvasses prior to priming.

 

How to make Traditional Rabbit Skin Glue Size

Soak 1 part Rabbit Skin Glue in 13 parts water for a minimum of 2 hours. Melt solution in a double boiler making sure the solution does not boil. Apply hot to desired support. Leave to dry for 24 hours before priming.

For information on stretching a canvas see How to Stretch a Canvas.

 

How to make Traditional Gesso

Take 80gms of Rabbit Skin Glue and add 1.1 Litres of water. Leave to swell for approximately 2 hours until it is a uniform beige colour. Keep the lid on this solution.

Melt the glue in a double boiler and leave to set in a cool place. Test it at room temperature, otherwise it may appear stronger than it really is. The set glue should look and feel like fruit jelly except a split in it with your finger should be firm and rough rather than smooth and tough. If the jelly is too strong add more water.

Gesso should be applied to non-flexible supports such as wooden boards, not stretched canvas as this will flex too much and the gesso willl crack. Size the board with the Rabbit Skin Glue Size that has been diluted with water by 50%. Sizing helps reduce absorbancy of the surface. Warm the size till it is hot (Do not boil!) and apply to the board sparingly. Size one side and the edges first and leave the board to dry flat. Once dry enough to turn over, size the other side and leave to dry thoroughly, betwen 3-12 hours.

Gesso needs to be white in order for the painting to be as bright as possible. Use Gilders Whiting as it has good dispersion in the glue size, dries to a fairly white finish and is relatively cheap. Replacing 10% of the Whiting with Titanium White pigment will improve the brightness and opacity of the gesso without affecting its structure.

Start with approx. 450 gms of whiting and 50 gms of Titanium pigment and mix whilst dry. This quantity of chalk/pigment and the earlier quantaties of Glue Size will make enough gesso for 3-4 coats on a 150cm x 125cm board. Heat the glue until it is hot. Transfer the glue into a spare pan and put the pigment mixture in the double boiler, keeping the boiler on the lowest heat possible. Pour enough glue into the mixed pigment to stir into a lump free paste. Make sure the pigment is thoroughly wet and mixed. Keep the lid on the mixture from now on or the gesso will thicken up and skin over from water evaporation.

Gesso is built up in layers, usually five, not less than three, to obtain a structure of decent thickness. Several thin layers are more stable than one thick one. Make the gesso in the morning so you can complete the boards in one day. Pin holes can develop if new gesso is applied over a fully dry coat. If the gesso thickens during the day because of evaporation of water add a little hot water (not glue) to keep it a thin single cream consistency. Otherwise the glue, and hence the gesso, will become too strong. It is important to keep the gesso the same strength because stronger layers over weaker ones will cause them to crack and pull off the board.

Stir very gently the gesso just before each application to prevent the pigment from settling to the bottom of the pan. Try not to whip in air bubbles as this can create pin holes. Brush on the first layer gently (not too vigourously) including the edges. Wash the brush out in between layers or it will set hard before using for the next coat. The gesso will be dry to touch in 10-20 minutes. Turn the board over and apply a coat to the reverse. Always apply an even number of coats on both sides to prevent warping of the board. Now, just build the layers up one by one, including the edges. Drying time can get a bit longer as the layers build up. Brush the third and subsequent layers at right angles to the previous coat. This helps to produce a level gesso ground.

Keep applying until the gesso is 1-2 mm thick or more, so that the dry gesso is thick enough to sand. Leave to dry thoroughly, between 12-24 hours