HOW TO ETCH STERLING SILVER
PART I : Introduction
What is Etching?
Etching is a traditional process of using an etchant (strong acid or mordant) to cut into unprotected parts of a metal surface to create a design in intaglio (incised) into the metal. The areas not to be etched are protected with a ‘resist’ which will protect it from being eaten away by the etchant. In my view, preparation is the key factor in a successful etch, and it takes time and patience.
Once etched, neutralised and cleaned, the etched metal can be made into jewellery; with tasks such as forming, soldering, setting, and finishing to follow.
Etching can also be achieved using an electro-etching process. It uses different chemicals and requires a controlled voltage output; as well as knowledge and investment to set it up. I won’t be covering that here. Today, I’m just going to cover the chemical etching, specifically of Sterling Silver using Ferric Nitrate (Fe(NO3)3). Ferric Nitrate is far safer than the traditional method of using Nitric Acid, which is highly controlled substance here in the UK.
The processes outlined in the following tutorial can be applied to the chemical etching of other non-ferrous metals. The only difference is the chemicals used to etch and to neutralise.
Ferric Chloride is used for copper, brass and nickel Silver (and sometimes stainless steel)
Ferric Nitrate used is for Fine and Sterling Silver, and some Silver alloys.
NB. To etch Gold, Nitric Acid and Hydrochloric Acid (Aqua Regia) or Potassium Iodide can be used. It’s not something I’ve tried. I would strongly advise outsourcing this process if you’re looking to etch Gold as it will need specialist knowledge, and seriously good safety practices.
Before I begin, let me tell you that my first encounter with etching was some 27-yrs ago at University when I encountered the magic of commercial Photo Etching. Wow! I saw the most beautiful hand drawn images transformed onto Silver. Beautiful, crisp, deep, clean images. In class, however, we were only shown how to etch copper using a black stop-out varnish. We were clumsy in our application; our etchings were shallow and pitted; and copper was never the metal for me.
Ever since though, etching has been a personal pursuit. The whole process of adding pattern to Silver has been the one constant in my journey. It’s been a journey of research, experimentation and practice; and I continue to learn and try new processes all the time. I have learnt to photo-etch at home, and tried every manner of resist I can imagine. Working as a Silversmith I can raise a bowl, set a stone, burnish a bezel to a mirror reflection; but etching is what I enjoy the most.
I’ve written this tutorial for beginners, and for those wanting to try a new resist technique. It’s not intended for seasoned Etchers, though I welcome their feedback. If you see errors or omissions please drop me a line and I will update it. If you know better ways, let me know. I’m always happy to learn.
I really can’t stress that what follows is just how I do it. There are other ways. None of this is new either. I’m just sharing the knowledge I have acquired from others; and the processes I’ve refined through my work. So, if you’re wanting to give it a go, read as much as you can from books and the internet. Experiment and find what works for you. You don’t need to copy all of my techniques step-by-step; but it will give you the fundamentals.
As I said, the tutorial is aimed at beginners, and outlines as many of the steps as possible. Some steps may require more understanding (and practice!) before achieving that perfect etch. I hope you find the tutorial useful, and use it as a guide and find your own way. Be warned, Ferric Nitrate crystals and solution stain. It won't harm you but it is indelible. Read the tutorial (links below), make a plan and work safe.
I should add, Etching isn’t hard. It just takes some knowledge, equipment, patience and time.
NB. I will only cover two types of resists in any detail in this tutorial, as these are the two that I use every week and are great for beginners and intermediate etchers. They are Nail Stamping Polish and digitally cut Vinyl. For other common resists, such as PnP there are experts in the field who have well documented processes on the web.