[Verdigris Using 5% Acid Solution]
Name: Robin Reich and Sophie Pitman
Date and Time:
2016.January.25
Location: Robin's kitchenSubject: Making Verdigris
I am following the recipe #159 on p.126 in Merrifield. The recipe does not specify that it is for verdigris, but it is listed as an alternative for a verdigris recipe above it, and later on in the recipe it speaks of how to use it on paper, referring to the finished product as verdigris.
Here are the instructions in the recipe:
Also to make green.—If you wish to make a green colour, take urine, or vinegar, and put it into a vase, and make a plate of brass, and place it over the liquid in the said vase so as not to touch the urine, and afterwards set the vase in a warm place and cover it up for 9 days, then take it out and collect the colour which is produced. This is tempered first with water, and afterwards with egg on wood or on walls. When you put verdigris upon paper, put cherry juice [or cervisia?] in it. If it is not of a fine green, mix viride terrenum. If it is too green, so as to be too dark, mix pure orpiment with it.
I chose to use red wine vinegar, the mildest acidity vinegar, for this project because of the alternative to use urine. As Professor Smith explained in class, although modern human urine is neutral if not basic, pre-and early-modern urine was acidic. Even then, I am guessing it was not extraordinarily acidic, and so I chose the mildest acid available. If this acid turns out not to achieve the desired result, it may be because early-modern urine was actually more acidic. If it works very well, better than those made with a stronger acid, we may be able to conclude that early-modern urine was of similar acidity.
When I opened the jar of red wine vinegar (5%) which I had brought home and had been sitting in my kitchen for several hours, the inside of the lid had several droplets of vinegar collected, suggesting that the environment inside the jar is very moist and creates a lot of vinegar vapor.
The recipe doesn’t specify how to suspend the copper in the jar, only that it should be above the liquid. An earlier recipe (which is for making blue using silver, but the recipe immediately following it, which is for verdigris, says to do the same thing using copper) says to suspend the metal plate on a thread made of the same metal. Having only the string, I instead folded and crimped (using my fingers) the copper plate over the string, and then held the string taut with one hand while I replaced the lid and tightened it with the other. I placed the jar in my kitchen underneath a towel, since the instructions say to cover it.
Name: Robin Reich and Sophie Pitman
Date and Time:
2016.February.8, 12:30 pm
Location: labSubject: Scraping and painting of the verdigris (using 2 samples of 5% solution verdigris)
- the two copper samples (prior to being exposed to the vinegar) varied in their texture - one was abraded, the other was shiny
- Patted dry the verdigris plates because both had been dipped in the acid
- scraped using palette knife until copper is visible
- mixed a sample each with walnut stand oil and cold-pressed linseed oil
- mulled on a glass plate with a glass muller, using a figure 8 motion and firm pressure
- stopped after a minute or so when the mixture looked smooth
- scraped verdigris and oil mixture off the muller using the palette knife and then onto paintbrush
- saturated paintbrush fully
- brushed onto board in a vertical motion until the board panel was fully covered, then textured half of it using a stippling motion (pushing the ends of the bristles directly into the board)
Observations:
Both pigment mixtures were very grainy - they likely were not mulled long enough. They were also quite dry and likely needed more oil. Both pigment mixtures appeared very textured on the board, with fully visible brush strokes.
The linseed oil resulted in a richer, more saturated color, that was a slightly darker and greener turquoise. The walnut stand oil created a less saturated color that spread less easily.
