How To Trace Well Even When It’s Hot

Common sense answers:

Tracing when it’s hot is far more difficult than in the cold because your paint is always drying out. So the first thing is of course, you look around for common sense answers to this problem.

Of course:

  1. You moisten your lump from time to time.
  2. You also keep it covered.
  3. And you do other things like you might use rubber stickers, or get a cooler light, use air-conditioning, or even remove your palette from the light-box altogether.

Is there something I add to our paint to slow down the speed with which it dries?


Someone suggested adding vinegar.

But I think vinegar actually makes the paint dry harder. This can be beneficial – say if you want to add another layer before your fire it – but it’s got nothing to do with keeping your paint flowing in the heat of summer.


Another person mentioned glycerine. Yes, I’ve also heard how glycerine improves the flow of paint. I tried it once. Don’t let me put you off. But me I am always looking for where to concentrate my energy. And certainly glycerine won’t help you unless you also focus your attention on organising your palette as we suggest.

How to organise your palette in the heat

Here’s how. Here’s how I suggest you arrange your palette:

  1. So you have your lump up one corner. Covered up when not in use.
  2. Then you have a thick pool of dark paint.
  3. Then you have your circle of paint in active use – this is the paint you use for tracing.
  4. And all around this circle, right up to the edges of the palette, there’s a film of water (put there periodically by your hake).

Have a good look at this picture, and then I’ll tell you all about it:

How to organise your palette in the heat

How to organise your palette in the heat

The cooling film of water around the edges

This film of water, it helps keep your palette cool, and it’s always there for you to draw on with your tracing brush (rather than always dipping your brush in your bowl of water, which can easily mean your brush absorbs too much).

The thick, dark pool

And this thick pool of dark paint, it’s always there for you to draw on when – after you’ve swirled in some extra water from the side – you need to adjust the colour of your tracing paint to keep it the same as the other strokes you’ve painted.

The whole process

So when it’s hot – and here we’ve had a long, hot summer: I know this works – I cut a few slices from my lump.

Then I wet my knife and grind the slices down to make a pool of dark and runny paste.

Next I use my hake to cover the remaining area of my palette with a thin film of water.

Finally I take my tracing brush and swirl and mix until I’ve made a good-sized circle of whatever consistency and darkness I need to trace with.

And now at last I start to trace.

After a few strokes, because it’s hot, the circle of tracing paint will start to dry. So now I swirl my brush around the edge which introduces water from the outside. And then I use my brush to draw down dark paint from the pool. Finally I just mix it all together.

Now two or three more strokes.

And so on …


From time to time, you take your palette knife – maybe wetting it a little to add more liquid – and re-grind your thick, dark pool.

And also take your hake, wetting it a little, and renew the surrounding film of water. Not too much, mind you. Just enough for your tracing brush to call on for the next few minutes.

This really works

The thing is, this works. Like this:

How to organise your palette in the heat

This works

There’s no need for glycerine.

Definitely no need for vinegar. Just these small and constant changes to your palette which you organise as I’ve shown you how.

All the best,

David Williams of Williams & Byrne, the glass painters

3 thoughts on “How To Trace Well Even When It’s Hot

  1. Glycerin, clove oil, lavender oil, pine oil … you just have to experiment and see what works best in your local environment. (Not too much or it takes forever to dry.)

    • I agree, Jim: whatever works. Now I know you aren’t suggesting adding oil to water to make it flow, so I just want to make that clear to even the most casual visitor to this post.

  2. Necesito información…trabajo en vitrofusión.-he adquirido un set de 9 colores de mica, pero tengo la duda con que poder mezclarlas para ponerlas sobre el vidrio, es un polvo sumamente fino y dice que debe usarse a 1425°F, no tengo la menor idea seria el número del cono en utilizar, mi horno es de cerámica con adaptación de resistencia para vitro, siempre utilizo cono -016-015 ó 014, depende del vidrio(sanwich2-2), no se si esta pregunta puede ser valida para ud. ya que lo que presenta con trabajos de vitrales con diseños…disculpe si no es el tema a tratar,hice una proeba pero no me gusto el terminado final..ojala y pueda hacerle varias preguntas al respecto, pues los conocimiento han sido pocos, pero lo que he logrado ha sido por mi propia investigación…gracia y en espera de su amabilidad…

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