Anyway, it's in the kiln firing right now. I've applied one layer of grey mat to the pieces, and removed the vines and ivy leaves:
After I fire them all I will repeat it with a second coating overall, so there is no clear glass and two tones of grey. I'm slightly tempted to pick out highlights again, and have three tones of grey, accept the deviation from the "co-geo-contemporaneous" panels. Three levels of shading is period, but I don't know that it was ever used for grisailles.
Using wine as a vehicle for the paint is fascinating. I am using a somewhat sweet white wine as a vintner friend suggested (specifically a moscato, very specifically the sparkling moscato from Cooper's Hawk Winery). The glass is sticky as a result. The paint is hard to scrub out; I'm not certain if that is because of the wine or if I inadvertently added more gum arabic than usual. I suspect the wine because Elskus mentions using table sugar as a binder. I imagine the sweetness of the wine could be introducing the additional grip. Because it's what was more local, I'm going to try a test batch of paint with cider instead of wine, though that isn't documented in any of the period sources. It makes sense and I can imagine a Norman glazier using it happily.
In order to scrub the pieces out I'm having to dip my hog bristle scrub into wine. It's really more like I'm rewetting the paint and removing it with a paper towel most of the time, where as with water I usually brush the dry dust off. If I remember correctly vinegar is described as giving a hard protective shell to the paint that can resist water (and save on firings). This seems to have a similar effect. I'm also glad it's a little cold for bugs, yet; I think plenty of them would be interested in the sugar. At Pennsic I will likely need to paint with vinegar (citable) or forego it for water. The third documentable item in Theophilus is urine, which I don't intend to try soon.
I'm somewhat relieved that I'm missing Midlands tomorrow; as I go I discovered a few pieces that were painted incorrectly. At least one, a corner, I was talked into leaving alone. Two pieces ended up with no ivy leaves, however, and they stand out when taken as a whole. After I get the shadings done I think I will go back over some of the pieces and strengthen lines, add in missing leaves, etc.
Pieces with highlights and some without (yet). Ignore the blotchiness, it's excess paint on the "table" and not actually blotchy paint on the glass
A close up of the pieces being fired right now