I’m sorry to hear about the blistering. Can I ask, What medium are you using?

Thank you.
Stephen

I have been experimenting with Reusche’s Blendable Bending enamels and am having a problem. Every time I fire the piece I get blisters or bubbles – ugly stuff.

Since I mainly do fusing I usually paint on Bullseye COE 90 clear 3m glass. I don’t know if this is important.

I’ve tried using various mediums. I’ve also tried painting lighter, thicker, with less medium, with more medium. I’ve ground it off, repainted and fired it again and still have problems … I’m firing at the recommended temperature – 1300 ° F temp.

I don’t think my kiln is firing higher then it is saying, so I’m at a loss as to what I should do next.

Is there something I could apply to the glass prior to painting?

And yes the glass is always clean before I paint!

Thanks,
Mavro Coggins

My solution when I needed to do this was to build the rainbow with glass frit in the various shades. This done using something akin to Tibetan sand painting technique. Laborious and care needed re compatibility of frits but the result looks good in both transmitted and reflected light – which is not always so.

Necessary of course to do the rainbow before any stained glass work as you will fusing (or sintering depending upon effect wanted) at temperatures above stain temps.

People can find a link to Kevin Petrie’s book in the ‘Useful Books’ box up above and on the right. It’s worth a read.

On the technical question of ceramic vs. glass paint, the handbook ‘Glass and Print’ by Kevin Petrie (A&C Black, London) 2006, has a body of helpful advice about chemical compatibility, firing profiles and techniques for ceramic and glass paints.

Granted, brush-painting and screen-printing aren’t always seen as being artistically compatible techniques, but the chemistry remains the same.

For screen-printing approaches, the cheaper ceramic paints are attractive for allowing generous quantities to be mixed, but I wouldn’t bet they’d behave as well on a brush as would top-grade glass paints mixed according to the recipes given by W&B.

On the other hand, there could be questions about how well glass paints would perform for screen-printing or decal-printing applications, quite apart from the frightening cost of mixing up big quantities.

In the school in Mexico we used ceramic pigments and mixed them with a frit whose number is #3419. This frit has the effect of making the ceramic pigments behave very much like glass pigments e.g. in terms of their coefficient of expansion.

In this way, the ceramic colors can be worked without problem, but the colors will change – depending on whether we see the glass with reflected or transmited light. I always make this very clear to the client. If the client wants to have painting on opaque glass and the view is with reflected light, then the glass is only serving as a canvas, and you might as well paint with oil, or acrylic or whatever medium you want.

But if you are going to see it with transmited light, the color only blocks the light – even the white behaves as grey in such conditions.

Regarding the use of oil: all paintings use pigment and a medium to bind the color. In oil painting on canvas, it is linseed oil. In glass is the pigments and the frit which, when heated, bind the color.

I assume that if you use some earth pigment of oil, and mix it with glass frit, then you can use oil. But I don’t know about the concentration of pigment, because the oil pigments have fillers like calcite to reduce the cost.

All the best,
Carlos

For us, and perhaps also for you, it is always necessary to begin with a design (which in its own turn has its origins in many hundreds of different ideas), and then find the means to express this design in (for us) stained glass (as opposed to sculpture, for example, because we are not sculptors).

So, if we were to create a design which demanded a rainbow effect, then we would certainly explore every avenue until we had found the necessary techniques.

My kind regards,
Muhammad