Sunday, 31 May 2015

Behind the Scenes - Acid Etching

With the help of my intern, Katie Watt, I've put together a post explaining a couple of the different ways I use the process of etching to add pattern and texture to my work.


Photo-etching is a process that uses light and acid to cut the design I’ve drawn into the silver.

By scanning my drawings and doing a little editing and tidying on Photoshop I can print my image on to acetate. The print quality will effect the final outcome so it’s always worth checking the black is super black and there are no marks on the acetate that shouldn’t be there.

Transferring the image from the acetate to the silver is made possible with light sensitive film. This film is attached to the silver - but beware - it’s got to be in a dark room under a “safe” red light otherwise the magic happens before we’re ready. The freshly prepared silver/film combination now has to be left to dry somewhere TOTALLY dark overnight - which means it’s onwards and upwards with some other project, time for a beer, or if I’m doing this at 2am (which is not uncommon) it’s time for bed!

How my workspace is set up for photo-etching.

In the morning I’m ready for stage two. The acetate goes on top of the silver/film and then that goes upside down on a light box where it’s blasted with the UV light. The film hardens when it is exposed to light but - and here is the key - the black ink protects the film from hardening. Therefore where the image was on the acetate the film will be soft and everywhere else will have hardened. Putting it in a soapy solution and giving it a little scrub with a toothbrush brushes off the unhardened film, exposing the silver so it’s ready for the acid.

The hardened film will now protect the silver from the acid so that only where the film has been washed away will the acid cut the silver. Read further on to find out a bit about how the acid works with the silver. For now I’ll just say the silver is submerged in the acid for the right amount of time and then the silver is left in caustic soda and water until the remaining film disintegrates.

The silver is ready to be etched as the blue film has hardened. 2. Going into the acid. 3. After it has been in the acid it goes into caustic soda and water which disintegrates the film.

Then I need to cut of the shape, maybe do some soldering, polish it up and what-not ….. And voila!! What was recently an idea in my head and a drawing in my sketchbook is now etched into the silver, creating a beautiful piece of handmade bespoke jewellery.

The finished Hare Pendant with a diamond set in the eye.

Traditional Etching

Kenmore and Niseach Kilt Pins - both traditionally etched.

Photo-etching gives you the opportunity to create designs digitally or by scanning drawings which can be edited with Photoshop if required. Another method that gives a more organic, hand drawn design is a more traditional method of etching. After coming up with a design I get the silver and completely cover it in black furniture polish. Once it is dry I use a scribe (a pointy metal tool) to scratch away the black polish as I freehand draw the design. The areas where I have scratched away the black polish are now unprotected and when I put the silver in the acid it will be these areas that will be cut into.

Oxidisation is a good way to really show off the etching as it gives a stark contrast in colour which reveals the interesting textures and helps them to stand out.

Acid Antics 

The acid reacts differently for many reasons. Of course the length of time the piece is in the acid is going to have a big effect. Temperature, the age of the acid, the position of the silver in acid and different types of acid all effect the way the acid behaves and need to be monitored to ensure the desired result is achieved.

The text on this Kilt Pin stands out as the area around it has been bitten away by acid. This was done using the traditional method of etching. The textured effect comes from the organic freehand scratching away of the black polish combined with the acid cutting unevenly due to the angle at which it sat in the acid pot.

Examples of each method :

The Oak Leaf Kilt Pin is a good example of how photo-etching can be really efficient. The pattern can be drawn by hand and then digitally expanded. Using digital software means that the pattern can be edited and perfected before being printed and etched. Someone else's handwriting can be replicated using photo-etching too. The music written on this Kilt Pin was hand written by the client’s bagpipe teacher - photo etching allows me to transfer this directly to the Kilt Pin making it even more special.

Photo-etching was used for the Hare as you can see here with the hand drawing transferred to a digital drawing. The Kenmore design was more suited to traditional etching as a rougher more textured organic pattern was desired.

So which way is best? It is important to choose the right method for each individual project which is usually based to the aesthetic of the finished product. There are loads of things to experiment with when etching - I’m always up for testing different things and seeing what works and I’m sure I’ll still be discovering new tips and tricks long into the future.