For my next project I decided to have a go with my Glassline Paints (all with 4mm window / float glass on this occasion) to:

1. try and salvage my heart hanging from the previous firing and test glassline on top of glass (on tin side too!)

The heart hanging from the last firing suffered from the foil evaporating more from the top hearts than the bottom ones. I have deduced that where there is space for air to escape, the foil will also ‘bubble away’ . I didn’t really like the look, so I decided to use it as a test piece for painting on glassline paints. So, although I was aware that the top of this piece was ‘tin side’ up (and enamels etc ‘react’ with the tin side according to everything you read, I thought I’d see what this meant. I painted on the red/ orange paint, around the hearts , doing several layers (leaving them to dry between each layer). I discovered you can easily ‘etch’ off paint where you don’t want it or to tidy up your design. I then added a layer of ‘crimson’ paint and this was far darker and nearer to the colour I wanted for the hearts. Thiswas then left to dry and was fired (result in bottom photo. ). Although I still didn’t like the piece that much (perhaps I should have trialled a silver / gold pilot pen on the top – a plan for next time as this is not meant to burn off in the kiln). But in others ways it was a success – the paint did indeed fuse to the top of the glass – there was no obvious reaction with the tin side of the glass , so I feel comfortable to add glassline paints to the top of glass.  (It was fired on a full fuse for float glass – programme 1 on the KCR2 controller) . This did devit the glass to some extent as this was the second full fuse firing of this piece – so I guess the advice would be to normally add the paint to the first full fuse firing.


2. make my own glassline paper and have a go at fusing this between layers of glass.

So my other experiment in this firing was to make some glassline paper. I purchased some small squares of bullseye thinfire paper from ebay and proceeded to paint the orange / red glassline paint onto the paper in a thin layer with a sponge type applicator (like a make-up sponge tool)/ I did two layers both sides of the paper (apparently when you purchase glassline paper it is coloured one side only – but when you make your own you can do both sides if this is important for your piece). I also added a bit of crimson paint in a third layer , again because I decided I wanted a darker colour, otherwise two layers I think would have been sufficient.

Once the paper was dry I cut some shapes out (see photo below). I did 3 small pieces , a heart, a cut out heart and a flower shape with alternating petals of the glass line paper and kitchen foil. These were put between 2 layers of 4mm float glass. i) The heart came out with a slight halo around it. My guess is that glassline paper (homemade at least) lets out some air bubbles around it – or maybe I hadn’t let the paper dry sufficiently.  But the piece was nice.  ii) The cut out heart was interesting. I had layered the paper right up to the edges of the glass. This did not work well. This prevented the edges of the glass fusing together (I guess I could have foreseen this – it is thinfire paper designed to prevent glass sticking to the kiln shelf!). So the learning here is to make sure the glassline paper is fully enclosed inside the layers of glass. iii) the flower came out really nicely and the combination with the foil petals added a delicate look that I really liked and no weird reactions between any of the materials.

3. test glassline paints between layers (non-tin side)

The last test in this kiln was a test of using glassline paints between two layers of glass. I did 3 stripes of differing colours). These again came out really nicely and this would make a nice pendant. Very simple and looks really nice.


Firing schedule was a full fuse for float glass preset programme on the KCR2 controller. This worked well.

1 Comment

  1. Nice experiments. As a general rule, any inclusion between two layers of glass that isn’t made of glass will need some space around it to allow the glass layers to fuse.

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