Traditional Gesso – Modern Practical Recipe
Ingredients:
Part – Prepared Rabbit Skin Glue by volume
1 Part – Dry Gypsum, the finest available.
1/5 Part – Dry Zinc White pigment.
Pre-mix the Zinc White Pigment thoroughly with the gypsum.·Separately, make the glue. Soak 2 parts of Rabbit Skin Glue granules in 10 parts cold tap water. Leave it to soak overnight for better results.
Place the container with soaked Rabbit Skin Glue in another containing hot water and allow to melt into a uniform jelly. Keep it warm but do not allow to boil.
Now slowly sprinkle the gypsum and zinc white mix through a sieve as if it were flour.
Do not stir. As the gypsum/pigment falls into the warm glue, it sinks to the bottom of the container. Sprinkle only small amounts at a time to enable the gypsum to actually absorb the glue.
When all the gypsum/pigment has been absorbed, stir very slowly with a wooden spoon, taking great care not to incorporate air bubbles.
Brush this gesso on a panel at right angles and up to 8 coats maximum.
Leave to dry and next day, polish the surface with garnet paper or a damp linen cloth pad in circular motions across the surface.
PLEASE NOTE: If you rush the procedure and incorporate air in the mix, after brushing it on the panel, the air bubbles blow up during the drying process. As the gesso hardens, it doesn’t have time to level out the holes left by the blown up air bubbles. You panel will look more like a notice-board upon which people leave notes stuck with pins, which renders it useless for oil painting.
The Old Flemish and Italian Masters Traditional Ground
Step #1 Making the Gypsum Biscuits:
Ingredients:
8 parts – water
1 part – finest gypsum powder or Plaster of Paris by volume.
Sprinkle the gypsum into the water through a sieve, stir continuously for at least 30 minutes or until the gypsum no longer sets.
Then stir this mix every 2 hours for that day and the following 2 days.
Cover with a damp cloth and leave it so for a full month, stirring it at least twice every day.
Take then a sieve large enough, place a cotton sheeting piece or muslin inside the sieve and pour the water and the gypsum and leave to drain all the water, squeezing with your hand gently until all the water has been poured off.
Make small cakes or balls of gypsum using your hands and let these cakes to dry thoroughly.
Step #2 Making the Gesso Sottile:
Have your Rabbit Skin Glue glue ready and warm, pour the cakes, one by one into the glue, and stir to mix them well, until you obtain a heavy double-cream consistency gesso.
Apply this gesso warm with a brush over degreased and already sized MDF or Masonite panels. Brush on 8 coats, at right angles. When you first brush a coat, the surface shines, wait it to dry until it becomes dull and matt before brushing the following coat. A total absolute maximum of 12 coats can be applied.
Leave the panel so prepared to dry completely until the following day or maybe for 2 days if necessary.
Finish by polishing the gesso with garnet paper or a pad of damp linen cloth, using circular movements across the entire surface. This technique will produce a marble touch effect just enough absorbent for oils.
PLEASE NOTE: The initial measure you used to measure the volume of gypsum and water for the cakes must be the same volume measure you use to measure the Rabbit Skin Glue glue. The quantities for the full gesso, i.e. the cakes and the glue, are 2 parts of Gypsum Cakes to 1 part Rabbit Skin Glue Glue. So, suppose you use a ½ pint glass. Measure ½ pint glass of Rabbit Skin Glue granules by volume and 10 x ½ pint glass of cold water, soak the granules and make the glue following one of the recipes previously given. Therefore, in keeping with the same ratio, measure 8 x ½ pint glass of water and 1 x ½ pint glass of dry gypsum powder (as indicated for making the cakes: 8 parts of water to 1 part of gypsum, by volume). It is important to keep the same measurement ratio all along in order to obtain the desired heavy double-cream consistency. You may have noticed that this ancient recipe does not include any white pigment, so your ground will not have the solid white opaque color, typical of a more modern traditional gesso. This, however, is not a shortcoming, as you will have a half tone ground from the onset to work on, by tracing a design on and applying a translucent Imprimatura.
Traditional Levkas Gesso
‘Levkas’ is derived fromo a Greek word meaning ‘white’.
Heat 1 Liter of Rabbit Skin Glue prepared the day before in a bain-marie; never boil.
Incorporate into it 2 pounds of alabaster powder. Use a wire wisk to get the lumps out.
Add 1/2 teasponn of linseed oil for flexibility.
Apply it to your panel warm in even crisscross layersand let it dry overnight.
Apply several more layers. After which the mixture can be applied with a putty knife. Add a bit of water if the Levkas becomes too thick to avoid cracking.
Sand to an egg shell finish.
