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Saturday, April 9, 2011

Gesso

Today, thanks to the generosity of Beloved Husband, I got something close to eight uninterrupted hours on the Thing. There was gesso. Possibly tonight there will be gold. Tomorrow will be more gesso, followed by white gold, and even more gesso followed by copper. And then there's the flat gilding to do. Muahahahaa.

What is gesso?  Super-thick paint.  The medieval recipe called for slaked plaster among other things (mix a batch of plaster.  Stir it too long and you will mess up the chemical reaction, and it will never set.  This is slaked plaster).  Modern people use gesso to help prepare canvases for oil painting, I think.  We medievalist wingnuts use gesso to create a raised surface, a little 3D action on our work, and then we put gold leaf on it.  The gold gets all flickery and flashy as the light hits it from different angles.

It's crazy time-consuming to do, and can get discouraging when you realize you've spent all this time on this one step and still have more to do.  But the gold takes care of all that.  Laying gold is not like painting at all.  Gold is instant gratification - lay it on the sticky gesso or whatever else you're using, hit it with a dry paintbrush to sweep away the bits that you aren't planning to keep, and poof! Instant shiny.

The only thing is, gold sticks to itself.  This is a blessing most of the time, because it lets you build up the layers of gold to get an almost velvety, luxuriant result (and yes, up close you can tell the difference between one layer of thin shiny metal and several layers of thin shiny metal.  You wouldn't think it would matter, but it does).  However, if you're working with more than one color of gold - say, 18K "white" gold as well as 23K regular gold - you can end up with your second color trying to adhere to and cover up the areas you did with your first color.

What this means for me is that I'm taking precautions by laying the gesso in stages, so the gold won't have any option but to go where I want for this first stage.  For the second color, I'll lay gesso down in the new areas, and then do something with the new color that we fancy artist types like to call aiming carefully.  As in, hit the target and don't miss.


Luckily, the third stage will be copper.  I've never worked with more than two metals before, but copper is nice because it doesn't stick to itself, nor to the gold.  This means that, a: I can put it on last and not have to worry about ruining my previous efforts, and b: the leaf itself starts out thicker (since you can't build on it with more layers) and therefore much, much sturdier. Just in my experience with my stuff, copper leaf is to gold leaf what aluminum foil is to copper leaf.
 
No, I won't be adding aluminum to this page.  Yes, dammit, I did just get the idea to try it sometime.
 
Here endeth the lesson.  I'm just so edjimacational, you know?
 
Tomorrow, lots and lots of shinies!

2 comments:

  1. Oh, it happened, all right. Pics are forthcoming - the piece needs to go to its recipient first, and that's Saturday.

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