Christine Woollacott
Christine Woollacott of Turritella Designs produces jewellery in her small studio in Toronto, Ontario, Canada. Multiples of the designs are created using handmade molds, and many of the cloisonné pieces are one-of-a-kind. Christine works mainly with fine silver and Thompson unleaded glass enamel. Transparent coloured glass enamel powder is fused to the metal at temperatures of over 1500 ⁰ Fahrenheit, to make colourful, luminous jewellery.
I’ve been experimenting with a few enamelling techniques in my studio lately. Today I finished a cute, simple charm using graphite and painting techniques with extra fine transparent colour. I really like the simplicity of drawing directly on the glass!
Simple Graphite on enamel charm.
The other day when I was at the bank, I noticed an elderly gentleman in the line before me had just deposited a giant box of Canadian pennies (which are no longer in circulation). Canadian pennies made from 1942 to 1996 have a very high percentage of copper (98%), which makes them excellent for testing enamel colours. When my turn at the bank counter arrived, I sheepishly asked if I could get $2 worth of the non-circulating pennies that had just been returned. The teller was wonderful, and said ‘sure’ without a blink. I felt badly for asking her to count out 200 coins, but the allure of easy enamel samples outweighed my embarrassment.
Transparent enamel colour tests on copper
The designs on the surface of the copper pennies make testing my current transparent enamel palette easier, because it allows me to judge which colours require a layer of clear flux enamel over the copper, and which colours can be applied directly to textured metal. This way, I can predict which colours will be effective with textural enamel techniques such as basse taille.
Transparent enamel colour tests on copper
A few years ago now, I purchased a sample set of Thompson enamel that included all of the medium expansion enamels for use on copper, gold, silver, low carbon steel and metal clay (SAMP-C, for those of you who might be interested). At the time, I made a decision to use only transparent colours, because I loved the play of light on the surface of the metal. I made fine silver test strips which I keep in my sketchbook, but I didn’t take the time to do copper tests. Tomorrow, I’ll finish doing the last 12 transparent colours in my regular transparent enamel palette, and then I will begin testing the opaque colours from the sample set.
Transparent enamel colour tests on copper
On another note – I find it very interesting how differently fine silver and copper behave when they are enamelled. I ended up firing my copper penny samples up to 1550 ⁰F, whereas for silver I would never go above 1510 ⁰F. When I’m working with reds, oranges and pinks on silver, I try to keep most of my firings around 1495 ⁰F so I don’t burn out the colour. Copper seems to require a higher firing, because it produces oxides at high temperatures that need to be absorbed by the glass enamel before the colour will reveal its true nature. It is particularly obvious when a clear flux enamel on copper is under-fired, because the undissolved oxides produce a very red colour beneath the glass. I’ll try to get a photo illustrating the dissolving copper oxides tomorrow.