Evidence for the versatility of the undercoat
Part 1
Last summer, designing two new windows - below, left and right - to go each side of the existing image of Saint Chad (middle) which was made some 30 years ago:
For those two new windows, left and right, someone might think to simply use unpainted glass.
But this wouldn’t really work, because the light would be uneven.
Horribly uneven ...
Direct sunlight would pour through those new windows on the left and right, but be changed and softened by the painting in the middle window:
The three windows wouldn’t balance.
They wouldn’t work together.
The outside pair would fight the saint.
This means you have to find a different way.
A way which brings the two new windows into harmony with the one which got there first.
The way we chose - and you might choose another - the way which we judged fitted with the painting on the middle window and also with the quantity of light within the church was:
To apply an undercoat - that is, a light wash of paint - to every individual piece of coloured glass.
And then, when the paint was dry, to adjust it to varying degrees and thus prevent monotony:
Either by gently rubbing dried paint away in places. We did this with our naked hands. Just rubbing it. Lightly. Until the paint shifted a little. Because gently changing depths of colour is pleasing to the human eye.
Or by using stencils to remove particular shapes through which the naked light would pour (though never so strongly as to fight the saint).
Stencils - cut from suitable material.
We already had several metal stencils from a project ages, ages old:
We also made new stencils using thick cardboard and a scalpel:
So you:
Apply the undercoat.
Let it dry.
Put the stencil on top.
Then use a brush to rub away the shape.
And use your hand to shade the paint and highlight.
Oh but it’s never as straight-forward as that when you’re matching light with an existing window!
So we had to do it once, fire the glass, see how it looked, then - in important places - do it all again, and fire the glass a second time, so that the windows looked good in their own right, and so they also balanced with the saint.
Now it’s the second layer we’ll show you in a moment.
The technique is just the same as for the first layer.
We’ll explain it first, because then the film will make more sense.
First, you apply a wash of paint to clean the fired glass - somehow, firing always leaves glass “greasy”:
And remember, this is the second layer: the glass already has a thin stencilled (and fired) undercoat on it. That's the paint you see already.
Second, apply the undercoat / wash of paint:
Next, because variety is wonderful, we now take a smaller hake and paint shadows around the edges:
And blend the light and dark paint together:
When the paint is dry, we put a stencil on the glass, aligning it with the paint / highlight from the first firing. Next, with a stiff brush, we remove the unfired paint:
Here it helps to wear a mask because the dust goes upwards to where you’re looking down on the light box.
Finally we use our hand to shade the paint and stencilled shape.
And that’s it - a decorated undercoat.
Strong enough to soften the passing light and blend the outside windows with the one inside:
So that's one way to use a stained-glass stencil - you do it on the light box.
But some of you will also like to see a different way of working.
On an easel:
With beeswax or plasticine (children’s modelling dough), you attach each piece of glass to a large, upright sheet of toughened glass.
Upright, you can see the whole window against natural light.
So in the film you see the whole process twice:
The first time on a light box.
The second time upright on an easel: cleaning, undercoat, shadow, blend, and stencil. (Here, David should have worn his mask but didn’t.)
Now when you take our foundation course Illuminate, we know some students expect to jump straight into tracing “because tracing is exciting - it's where the action is”.
But in fact we start with the undercoat and practise it for a week - yes, a whole week - then every week thereafter you practise it some more.
You see, the undercoat is not just a wonderful surface on which to trace and flood (which Illuminate explains in later weeks).
Thus the undercoat - just by itself, when you shade or stencil it - is a lovely way to decorate your coloured glass.
Here's the top-section of the right-hand window, still in our studio, after it was leaded:
That's why, inside Illuminate, students learn so much about the undercoat / wash:
Because it very, very useful.
And now for the film. The first time horizontal on a light box. The second time upright on an easel.
We only speak from time to time because now you know the process and can therefore concentrate just on what you see:
P.S. Here's glass from the same windows with highlights which you can make with a lice comb - yes, I do mean the kind of metal comb which parents sometimes need to use to remove lice from their toddlers' hair.
We’re sure you'll invent your own techniques.
P.P.S. If you found this post useful, here’s part 2:
