A Lump, not a Teaspoonful is What You (Mostly) Need

Not a teaspoonful!

Hello – and I’m glad you want the extra homework. That’s the way to go.

Yes, we were talking about glass paint.

I said for you to mix a lump (not a teaspoonful), like this:

Stained glass paint

Well, mostly (not always – when you really do only need a line or two in a particular colour, of course just mix a small amount.)

But that’s not what I’m talking to you about here. What I’m talking about is your standard mix of glass paint: the glass paint you’ll use most days to do your own work. That’s when you need a lump.

Now why do you think a lump will work better than a teaspoonful?

Here’s what I know …

A lump dries out more slowly than a teaspoonful – something to do with the ratio between surface area and volume if you’re wondering. This is important. Once glass paint dries, you’re back to dealing with dust again. And, when you re-mix it, dust flies around, which is bad for your lungs, a waste of money and bad for the atmosphere. So anything you can do to keep it moist and workable for longer – is a good thing. That’s one reason I say to mix a lump and not a teaspoonful: it dries out far more slowly, and it only needs a little on-going maintenance to keep it in good shape.

Does that make sense?


Now let’s imagine you’ve got this lump of glass paint sitting up one end of your palette.

Thinking ahead …

Now I know this is jumping ahead, but this is how you’ll see my point. OK, so, as it is, your lump is far too thick to paint with.

Just so – it’s not for painting with … this is your “concentrate”.

So what do you do next?

The answer is, you make whatever kind of paint you need.

But I thought we’d already ‘made’ the paint … ?”

No, you’ve just prepared the concentrate.

So what you do now is, you cut off a slice (or two, or several), pull it somewhere else on the palette where you can work with it, and grind and dilute it to whatever consistency you need.

What do you mean by ‘whatever consistency I need’?”

You must get used to this: glass paint is unlike any other medium you’ll work with.

It’s up to you how wet or dry it is. It’s up to you how light or dark it is. You decide. You make it as you want it. I accept this is sometimes difficult to decide. I also say: it’s what makes glass painting so interesting for you the painter – nothing is ready-made. You’re in charge here. Only you.

Now the books tell you to mix a teaspoonful because they want you to trace your outlines, then fire the glass.

But I don’t want that for you. I want something far more. Like I said, I want you to know how to do all your tracing and shading, front and back, with water and with oil … in just one firing.

And yes indeed, the teacher at art college tells his students to mix a teaspoonful because there are 12 of them in a class, and they only have 8 ounces a year to share between them.

But you and I are working together, one-to-one, and I want you to learn the techniques which really work. I don’t give a fig-leaf about techniques which colleges are forced to teach because of annual budgets. (Actually, I’m sorry for them; but if it were me, I’d figure out a way of getting more paint. I’d do anything rather than betray my students.)

So that’s why I say: mix a lump, then dilute it a little at a time to whatever consistency you need … thick, thin, light, dark, dry, runny … You’re in charge here. Only you. (Lots more on this – another time.)

And for now, in closing, let me say this.

Get the right brand of glass paint

Not all makes or brands of glass paint are good to make a lump with. Some of them just don’t hold their shape. So straight away let me tell you what I mostly use.

And remember I don’t get commission from anywhere or anyone. I just tell you what works for me.

My all-purpose mix is 3 parts Reusche tracing black (DE401) and 1 part Reusche umber brown (DE402).

This is my “work-horse” lump.

And if Reusche offered me a free holiday in return for my endorsement, I’d carry on using them – I’d have to: they’re the best … but I’d just stop mentioning their name to you.

(And no: I would not accept the free holiday.)

When you want to know more about how to mix, test, store and revive a perfect lump of glass paint, please see here.

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6 thoughts on “A Lump, not a Teaspoonful is What You (Mostly) Need

  1. This is a great article: I will use a lump of paint from now on always!

    Do you use a blow drier to dry your trace-lines and matts? Or do you do every single thing while everything is wet, and then you fire it? (I took a workshop, and the teacher always blow-dried the tracings and matts.)

  2. Dear David and Stephen,

    Thank you for your emails. I have just discovered your site. I am ordering the DVDs and looking forward to them.

    … But I must say … you two are a big tease!! I CANNOT wait for the next round … be swift … pleeeeeaaaase!

  3. Hi Stephen, I am completely new to glasspainting and made a complete mess of mixing a TEASPOON (as per instruction) of paint – yes it dried out before I could put it to use. In your guidance, you say I can dilute the lump, a little at a time, to the consistency that I want. Is there a danger I could dilute it too much and weaken the effectiveness of the gum Arabic?

    Kathy May

    • Hi Kathy,

      So I understand you made a teaspoonful of glass paint per someone’s instruction – and now it’s dried out.

      You want to revive it.

      And you ask whether, by adding extra water, there is a danger you will dilute the gum Arabic too much.

      Let’s go back one step.

      The way I see it, because you only mixed a teaspoonful of glass paint, then, even if it’s dried out, you’ll only need a little water to turn it into liquid once again.

      So where I’m going with this observation is, you aren’t diluting your paint very much at all.

      And that’s about as much as I can say with any confidence. I know you explicitly ask about gum. But the answer all depends on how much gum there was to start with, and also with how big / small your “teaspoon” is.

      So I suggest you add water a few drops at a time, grinding it all together, then adding more if you need to.

      When you have a consistency you can trace with, load your brush and work with it a while. Then, when your lines have dried, test them to see how much gum there is in them: rub them very, very gently, and see how firm they are.

      I hope this answer is helpful. This is a big, important topic – that’s why we filmed a whole course on how to mix paint really well.