Lesson 7: Applying Paint and Etching Cream to Glass
Working with Transparent Paint
Up until now, we have only dealt with transparent paints in fabric painting - and even with those we were painting on an opaque surface. When you are using glass as your surface you are painting transparent onto transparent. And you will discover quickly (as I did) that clear glass is the only glass you can see these paints on. Don't try prettying up a nice cobalt blue bottle as the paint won't even show up.
This is good in that it takes advantage of the inherent characteristics of glass. You can see through it - even the painted parts.
Working out Shadows and Highlights in Transparency
It is a bit awkward at first, though, because the colors simply don't work as we are accustomed to. Apply one color over the other and you create a new color. This can be very useful - to create a violet you can brush blue over red instead of having to mix them. You can also mix the colors for a different effect. In fact, you can get extremely creative with these paints.
It takes some time to realize this, and to work out how to highlight and shadow. I tend to start with my lightest colors, generally base coating the entire surface. I then add shading with the darker colors. If I need more highlighting, I use white.
The Pebeo paints which I use are unlike most in that even the white is actually fairly transparent. So it lightens the underlying color, but not as dramatically as the highlight you would get when working with opaque paints. In fact, the white looks more like etched (frosted) glass than it does white anything.
Another way to achieve shading and highlighting is to double load or float the colors onto your brush, so that you achieve both in a single stroke. This works very well on small areas, or where you only need a fairly small highlight or shadow.
You may also discover that a single coat of a transparent paint will be much less intense in color that you may have anticipated. Two coats can make a dramatic difference. But be careful of when you apply them. Most glass paints dry to the tacky stage very quickly. If you aren't extremely swift with the second coat, you may end up pulling up the base coat. So you are better off waiting half an hour or so until the underlying coat is dry enough that you can add more color safely.
Avoiding Unfixable Errors
Some artists even prefer to bake the first layers of color then go back and add new color, baking that, etc. until they have done all the shading and highlighting they want. By baking, you achieve two advantages. The first is that the heat will often enrich and deepen the color - you may find that what seemed like too little is actually enough. But even if you decide you need to add, once your undercoat is baked it is also permanent and nothing you do now can disturb it. You can even wipe off mistakes safely.
With some brands of transparent paint, you can use the white to achieve some measure of opacity. Until you get accustomed to working with completely transparent paint, this may be a good way to get started.
If baking, follow manufacturers directions carefully. Make sure your oven temperature is accurate and bake no longer than the recommended time or your paint may get a burnt appearance. You'll often find that your colors blend a bit better and that the color intensifies after baking.
Don't preheat your oven - let your glass warm up along with the oven. And let it cool down before removing your work. A sudden emergence into a cool room could cause the glass to crack.
