This is an experimental project to see if adding a border ring to a domed silver disc improves the overall result of the finished enamel. When I created the set of enamel doorknobs I didn't add a border ring, so the cloisonné wires had to be ground back to be quite thin near the perimeter of the piece where the enamel became thinner, or in some cases, left with a slightly non-smooth surface. This doorknob (above) shows the problem, albeit minor, but to the perfectionist something to improve!

Take a look at the transparent green grape (or smartie!) on the left, the opaque white enamel just below is struggling to match the height level of the silver wire since there is nothing to hold it back at the silver disc's border. With a border the enamel will be able to level out and form a uniform thickness, which should give better finish.

The other reason for trying a border is to add extra strength during the firing process. I'm interested if I put a border around the piece then I may not need to dome the silver disc at all. This is particularly interesting for creating a watch dial where the doming makes it difficult to connect the hands with the movement mechanism.

Here's a step-by-step on the project. I've already uploaded the photo's here but I'll put more detail in this blog and the ones to follow.

I found a great picture on Pinterest of an Amazon frog:

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and did a painting, at the scale of the final piece (round with 40mm diameter), onto paper.

I traced around the edges of the main design and re-drew the frog as a simplified line drawing. These will be the lines for the cloisonné wire to follow.

Onto a pure silver disc, 40mm diameter, I painted Chinese White water colour. The silver has to be really clean for the paint to go on properly. When it was dry I traced the lines onto the white paint using tracing paper and pencil and then engraved the outline using a detailing 96° V-shaped graver.

I've been experimenting with guilloché and thought this was a good place to try it out. The guilloché has been done with an adapted Sherline Vertical Mill CNC (Computer Numerical Control) with a specially ground graver bit. I programmed the CNC to do sinusoids with varying phase offsets to give the pattern - a beautiful use of maths and phasors.

Here's the piece again, at an angle, so you can see more of the engraving. There's a stipple on the top part of the frog's body which should catch the light and there's some wood texture lines at the bottom, all of which I hope will give some sparkle and delight!