Drachenwald Laurels' Arts Challenge: Heraldic textiles for your camp, Part II

 

So, as I'm digging through our Good Friend Cennini's book, there's a lot of flipping back and forth from the bit on silk painting to the index to various other points in an effort to understand what all of the layers are and how to make them. I suppose I should be up front about the part where I don't intend to make the various goops I'll need, but I absolutely want to understand them so I can make the best choices possible for the modern equivalents.

It's like a sandwich

As I mentioned in the previous post, Cennini is fairly explicit on how to paint on silk. I'll need size, a gesso mixture, bole, paint or gilding, mordant, and varnish. These each serve a variety of purposes, so let's unpack them a bit.

Size

Size has two general purposes in this scenario. The first is to get into the pores of the fibres to seal the fabric and make it less absorbent. This will prepare the silk to take the gesso layers. Cennini gives a recipe for size that involves boiling sheep parchment in water until it makes a sticky sort of glaze: 

     First take a size made of clippings of sheep parchments, boiled until one part remains out of three. Test it with the palms of your hands; and when you find that one palm sticks to the other, it will be right. Strain it two or three times. Then take a casserole half full of this size, and the third <part> water, and get it boiling hot. Then apply this size to...any sort of work which you have to gesso, using a large soft bristle brush. Then let it dry.

He then says to put two more coats of strong size over top of this, letting it thoroughly dry between coats, 'and it will come out perfectly sized.' I wish this also worked for clothes.

The other thing size does is create a slightly sticky surface on the gesso for gilding, so I'll get to use it twice, as I've decided that of course I need to have a shiny banner.

Gesso

'Gesso' comes from the Italian word for 'plaster' and is used to help smooth rougher surfaces, like wood and canvas, so gilding and paint will stick. It's a plaster-like goop made primarily of glue and chalk, which has the added bonus of being fairly flexible, so the paint is less likely to crack if the fabric gets rolled up. Which it will, because I'll be packing this bad boy along to events. It tends to come in two forms: gesso grosso and gesso sottile, with the former being a coarser bottom layer, and the latter giving a smoother, finer finish.

Bole

Bole is typically the layer directly under gilding. It's slightly coloured, so provides a base tint if any of the gilding wears away. It's also able to be sanded to incredible smoothness, which makes the burnished gilding look way better. 

Mordant

Y'all...I learned a thing! I'm familiar with mordant being a thing with dyeing fabric, but I'd not heard it used in a painting/gilding setting. So, where bole and size are used to create a surface for large swathes of gilding which would be done before any additional painting, mordant is used after paint for small gilded embellishments. Armed with this new information, I can say that I'm unlikely to need it in this project, but it's definitely a thing I'm glad to know.

Varnish

Cennini mentions varnish a lot, in relation to finishing off a work, but he says bugger all about how to make it, or even just what it's made of. So, TO THE INTERNET!

What I discovered is, as with its modern descendants, the main purpose of varnish is to seal and protect. Renaissance varnishes could be made from a variety of things, from egg white to resins. They generally dry clear, but - as we know from looking at old paintings today - they can add some tonality, and may colour over time. Some are best suited for indoor use, and others can withstand a bit of weather.

Next steps

My cunning plan is really starting to come together, now. I've decided some key factors: I'll use my device, not a badge (this time), I'm going to use pre-dyed fabric for the ground, and I'm going to gild my device elements, because why would I not?

I now need to acquire a frame, fabric, gessos, size, and bole. Once I've amassed the supplies, it will be GAME ON. I'm getting excited, now!