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-   -   Help! Traditional Grounds for Painting (http://www.wetcanvas.com/forums/showthread.php?t=1464543)

craigchivers 04-13-2019 02:45 AM

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

DigitalEchoes 10-07-2019 04:51 PM

Re: Help! Traditional Grounds for Painting
I am certain there are much more experienced persons on here who can provide more and better information, but I am wondering if your thick gesso is a result of using different compounds? (particularly the Holbeins)

I use rabbit skin or hide glue base, mixed with extra fine calcium carbonate, in a ratio that is about 1:2 of liquid to dry, and it is a medium-ish consistency for applying several coats of gesso. I sometimes use titanium or zinc white, or combine with another pigment(ie green earth, browns, or some such to give a tint to the base), and I dont usually have an issue. However, that being said, I don't have any issue with adding a few more mls of water to the gesso if it gets too thick - water will evaporate so the most important thing is to make sure you have the ratio of glue to chalk.

In looking into your materials, the holbeins is made of calcium sulphate, not the much more commonly used calcium carbonate. I am not familiar with the specific chemical properties of calcium sulphate, which is gypsum, but considering how gypsum is used (think drywall plaster and sheetrock) and how incredibly absorbing it is, maybe you need a modified recipe to use your specific base.

Marble dust or limestone are also calcium carbonate, at the chemical level. I have found marble dust works about the same in my gesso recipe, but that the tooth is not as fine as buying something specifically labelled calcium carbonate.

Good luck with your gesso! Maybe you could contact holbeins directly and they can offer advice on mixing their specific gesso, since they have a different chemical composition than most others. (at least that I have seen)

**EDIT: after poking around a bit online (curious about the Holbeins gesso) it seems that at least one recipe using this gesso is an oil gesso- using linseed and egg yolk (something I have never before seen used in the gesso component- and i make my own gessoed panels for both oils and egg tempera!) in combination with water, rsg, and the bologna gesso.


Maybe this can help you? Good luck!

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