This was a bit off-putting.
I am, mundanely, a computer geek. I don't hunt for my food. I have two cats and a beagle. I like animals. I'm not naive, I know what tasty bacon comes from and I appreciate when hunter friends share venison with me. But I know I probably couldn't field dress an animal unless my survival depended on it. So, this ended up being a slight bit sad for me, handling little furry tails.
Cennini is the earliest primary source I have on actually making paintbrushes. Consulting a friendly C&I Laurel suggested this was fine. She said that before him no one probably thought writing it down was necessary because of the normal apprenticeship process.
The short version he detailed is you use minever fur and a tapered stick and join them using a quill as the ferrule. They are joined by some thread lashing.
He wrote that you must take the tails of minever (stoats) and remove the ends, which have the longest fur. Then take the fur from the middle. Wet them in a goblet of clean water and press them into bunches. Then you take quills of varying sizes, vulture, goose, dove, and so on. Put a bunch of fur of the appropriate size into the quill, and wrap it with silk thread*. Then, insert a small stick of wood* into the other end, and again lash it on with the thread. This yields a minever brush that he says can be trimmed into a number of shapes appropriate for different jobs.
I had to research what a minever was to understand it was a stoat. I managed to find someone selling stoat tails online, who had three of them. None of the pictures of stoats or tails had a scale reference, so I pictured something large, like a ferret or racoon tail. I was a bit surprised:
Stoat tails in a pretty standard adult male hand.
Now I see why he talked about using the tails of five or six of them for a large brush.... Heralds, do these look familiar at all? The winter coat of the stoat is called ermine. I can't imagine how many tails it took to trim a garment!
With only three tails to work with, I won't be making any large brushes. I also won't be painting any large murals, so I don't feel particularly worried about this. I plucked out a lot of the fur from the ends and middle of one tail. Wet the fur and pressed it into clumps on my table.
Then I turned to my bag of quills.
I hadn't realized that very little of the quill is hollow. I cut one at the far end only to discover I wasn't putting a stick into it. The picture is not ideal, but the quill wasn't hollow at this point.
I found it a bit confusing at this point. He calls for a thin wooden stick, tapered, to be inserted and tied onto the quill and for my purposes I don't know why that is necessary. Despite Cennini's directions being in the glass section of Il Libro dell'Arte I wonder if the brushes he describe aren't used for larger paintings? He does describe a variety of sizes. Without having compared every feather type personally (vulture and dove, for example), some of the larger end seem larger than the modern brush sizes commonly recommended for glass painting by the "modern masters" and I notice a great deal of variety between the goose quills I have. At the smaller end, the feather itself seems to be a perfectly fine "stick." Their only obvious drawback is that the opposite end won't hold up for stickwork, scratching out paint as needed.
As he described, I tied the waxed silk thread on and used it in a form of lashing. He calls for a "knot" and not a "lashing" and I don't know if they would have even recognized a difference. As an Eagle Scout I know them as two different things and I was initially tempted to use a form of lashing. In hindsight, what I was going to do would have poorly secured the fur to the quill. Instead I tied a simple square knot to start. From the written description I thought the idea was to tie the thread so tightly it constricted the quill. That was NOT happening. I didn't test the strength of the thread but I attempted to tie the knot directly over the quill first and pulled tight. I got nowhere [Edit: see "**" below]. I then rechecked the text, wondering if the quills were supposed to be soaked to make them workable, but that wasn't indicated. I tried again, tying the knot directly over the fur and tightly binding the hairs into a bundle. I then wrapped my way down the bundle, over the point of the end of the quill and down. I ended with a simple overhand knot, thinking again a little wax to seal it "makes sense." I didn't use that, however, as it wasn't called for.
My first quill brush, with Cennini's book as a backdrop.
I only have a few quills that may be large enough to accommodate both the fur and a tapered stick handle. For the purposes of this small brush I have left the quill as the handle. I think the next one, which will be larger and use the tails of the other two, will have the wooden handle. Likely so too will the hog-bristle brush I plan to make tomorrow as well.
An edit will come later this month (March 2014) about the results of painting with this brush.
Thoughts and Lessons Learned (in no particular order or relevance):
- I'm not sure why waxed silk thread was called for. Silk is known to be strong and the waxing didn't add any perceptible quality to it, though admittedly I'm not sure I've ever handled plain silk thread. It didn't seem stiffer than cotton thread. I may try to give it hell and see what happens. [**Edit: I took a length of the thread, tied an overhand knot and put it on the quill. I wrapped the long ends over my fingers and pulled slowly, but with all my might. The thread snapped LONG before the quill gave any sign of contracting neatly. I tried again with a doubled length of thread, same result. Trying on the thinnest portion did nothing that would secure bristles either]
- What is the impact of North American vs European quills? Are geese significantly different?
- Man, a little glue would do wonders. I'm not sure why they wouldn't have used that. Maybe glue was not as available or affordable in period? Might be another question for a C&I laurel. Mostly irrelevant, but a quick review of an episode of How It's Made shows that modern brushes are not held in using compression, but glue... at least, the large ones. [Edit: The knowledgeable and skilled Estelle de la Mer has informed me that period glues would likely have become weak quickly due to constant exposure to moisure.
- I'm curious how the quills compare. I can't find European turtle dove feathers available, but NorAm mourning doves are. I've ordered a few. I suspect the quills will be significantly smaller. The average length of the two breeds is only a few centimeters different.
- I will be interested to see how the hog bristle brushes turn out. The C&I Laurel friend I spoke to suggested that they are very suitable for glass painting (contrary to a remark I made) because they should apply the paint thick enough to conceal the brush strokes. To be honest I initially thought that was incorrect because we use a badger blender to smooth out those strokes. Then I realized, none of the period sources I've ever seen describe a badger blender. That is what I get for doubting her :)