Help! Traditional Grounds for Painting
If someone has experience with traditional grounds for painting I would very much appreciate some help.
I have been trying to make a traditional gesso ground and mainly following Massey, but have also read Doerner and Mayer. I did take an undergrad course in Historical Techniques back in the day at York U in Toronto. I really wish I still had contact with my teacher who was a professional art restorer
Now the size is simple enough rabbit skin soaked in water 1:10 and then heated in a double boiler.
Now the gesso is where things get weird. Using a 1:1:1 rabbit skin glue: plaster (i'm using Holbein Gesso Bologna) zinc this formula will always make a really thick paste! I've no idea how you can mix 2 parts solid with 1 part liquid and get anything but a very strong paste and then to try and use a brush makes it very rough and unwieldy. The formulas also say to let the gesso cool which seems impossible as when it cools even the slightest it gets too hard to brush. I've tried to apply it with a scrapper / spatula and that works a bit easier but again the recipes always call for it to be brushed. I have been able to get a few coats on a wood panel but as it's so rough I end up trying to alter the recipe to make it more fluid either by increasing the amount or rabbit skin or by diluting the whole thing in water, but when I do this it cracks and then it's game over time to throw the panel out and start again! I've tried to use less zinc to plaster as the zinc is certainly harder makes sanding almost impossible for all but the most finest surface change. Also I'm wondering if the hardness of the zinc is precipitating the cracking, but again the recipes call for it and it certainly makes it a much more brilliant white than just with the plaster.
Any help or advice would be great!
Cheers and happy painting