Back in January I tried making a faux basse-taille (metal and enamel) painting, but I was disappointed with the finish as it lost its metallic shine and enamel clarity. There were a few things I was fairly sure were mistakes so I did some tests to see if I could work out a better method.
The first mistake was that I shaped the clay, brushed it with metallic powder and added the tinted liquid clay all before the first bake. This meant that the metal powder brushed off the base and mixed with the liquid clay making it cloudy (particularly visible on the crest of the hill). The next problem was that when I used the heat gun to try to clarify the liquid clay it caused blisters.
For the first test piece I made (left) I baked the clay with the metallic powder on before adding the liquid clay and baking again. Then I very cautiously used the heat gun. It made no difference. Then I tried the heat gun more boldly. Again no improvement. Finally I used some Renaissance Wax and this did bring out the colour and shine.
Then I compared using varnish before adding the liquid clay (after first baking the metal powder on), and if skipping the heat gun made any difference. The two central moons indicate the heat gun does not make much difference (I finished both with wax). Using the varnish did make a difference – primarily I could leave the raised “metal” areas exposed without a layer of liquid clay for protection so this improved th shine of the piece. For the last moon on the right I used glass paint instead of liquid clay and this was much closer to the finish I was looking for.
Next I compared using the glass paint with and without a layer of varnish underneath. Again with the varnish I could leave the raised areas without paint but more importantly the one without the varnish now has a slightly sticky surface (I made these in late January). I did not use wax on either of these.
Finally I wanted to test if the base clay had an effect on the finished piece. I compared the metallic powder and varnish with silver acrylic paint. When using the powder the base colour did not seem to make a big difference, but with the paint it did. The paint also tended to be more streaky.
In conclusion the metal powder gives a smoother finish than the paint and the colour of the base clay is less visible; the varnish gives a better finish and may prevent stickiness; the heat gun makes no difference (but the wax does); the glass paint has much better clarity and shine than the liquid clay.
I just need to wait a while to confirm whether the varnish continues to prevent stickiness so I’ll put these in quarantine for now. Speaking of which it has now been over a year since my experiments with DIY expanding foam and there does not seem to be any adverse reaction. Perhaps it’s time for me to dust them off and use them?