In the first of the silversmithing classes at Leeds, our tutor started showing us how to make a photoetched bangle and ring. I’ve never done any sort of etching before but I’ve always liked the effect and have collected quite a few Pinterest pictures of other people’s efforts. A good explanation and description of photoetching and how it can be used in jewellery making is on Jess Todd’s blog from last year.
Preparing the metal plates
During the first class we prepared the metal. One piece of copper around 19cm long and 3.5cm wide and a small piece of silver sheet around 9cm by 1cm. Preparation involved scrubbing the metal with a scouring pad and Vim! This was to take any grease or oxidation away so that a photosenstive film applied later would be able to stick properly.
The blue photosensitive film looked a bit like pale blue clingfilm and was put onto the metal after it had been sprayed with water. We used a roller to smooth away any air bubbles and a craft knife to cut round the metal to make the film exactly the size of the sheet. This was then left until the following week to dry properly to make it less likely that the film would lift subsequently.
Our homework for the first week was to look for a design to etch onto each piece.
I did some searching on Pinterest and thought about it during the week but must admit I only got round to preparing the images during the afternoon before the next class. Typical.
I chose to do a peacock feather design on the bangle and chose a copyright free image of a single feather, which I then processed in PhotoScape to make it a higher contrast image and smaller. I then combined two right facing feathers with two left facing feathers to make the design.
We needed to print all the images at approximately the correct size and then transfer them using the Leeds College of Art photocopier onto a sheet of acetate. The transparent image was then taped to the metal sheets we’d prepared last time.
Using the college mega technology
We then got to use a light box of massive proportions in the printing department. This was about twice as tall and four times the volume of a chest freezer. After the plates were placed on the surface, face down, the lid was closed and locked and a strong vacuum was turned on. This sucked each of the plates down so that when the strong light came on, there was very little leakage around the acetate images.
It took only a few seconds and we were ready to put the plates into developing solution – a small quantity of sodium carbonate in warm water in two photo developing trays. First we had to peel a layer of the photosensitive film away and then put the plates into the developing solution face up. After a few minutes, the images magically appeared. When we were happy with the image we sprayed with vinegar to neutralise the alkali and stop the reaction. After rinsing with water and touching up any patches that had come away from the image, the plates were then labelled to be processed in nitric acid during the week to do the actual etching.
Next week we will get our finished plates back, ready to make into jewellery. My plan is to curve the copper into a bangle – I’ll probably have to round the ends first – and then to patinate the surface and colour using alcohol inks so that the peacock feathers are picked out in shades of blue, green and purple.