acrylic resist etching on steel plates

 

an artist's journey

 

Out of a need to move on from traditional etching techniques I started researching Acrylic Resist Etching (ARE) on steel plates in Oct. 2009.

 

I discovered an alternative system that offers a wide range of creative options for mark making on plates and a much healthier and safer way of biting steel plates.

 

My first experiments were promising and after months of testing, studying and researching I now have created a number of images on plates that are comparable with the ones I used to make in the traditional ways (technically speaking).

 

Making the plates with the ARE system meant learning a new skill to achieve an old goal! It was a puzzling experience at times. Often it has been about not much more than replacing the familiar materials with new ones and using a different biting mordant instead of a nitric acid bath.

 

More often it has been a steep learning curve.

 

Researching the field and talking to other etchers, that have worked with ARE for a long time gave me information, endless amounts of recipes, but not necessary the one that would work for my purpose and in the circumstances of the studio. Learning to use a scientific approach towards my experiments and the way I record my findings proved a very important tool.

 

Most workshops bite zinc, aluminium, copper or brass plates, but not steel.

 

I have always preferred steel to zinc, because steel has a coarser grain and is harder. Furthermore the plates can be printed in colour and is also the cheaper metal to purches.

 

This meant that recipes I researched or others shared with me did not work with my steel plates. I had to adjust ingredients and the way I was treating my plates.

 

Getting used to the new materials that feel very different in consistency, behave different, smell different, clean off in a different way and are applied differently proved to be a challenge. BUT the results are stunning.  ARE offers additional and new creative options for plate making. It’s like a new artistic playground.

 

It is worth the effort and continues to be a fascinating creative journey.

 

The principle:

 

Etching bath = Biting mordant

 

In practical terms ARE means using acrylic liquid varnishes/ emulsions as grounds and acrylic spray-varnishes to replace the traditional resin used to create aquatints (for tonal ranges). The classic nitric acid bath for biting the steel plates is replaced by a copper sulphate- salt solution (developed by Friedhard Kiekeben in 2002 (Salin Sulfate Etch @ F.K. 2002).

 

Copper sulphate – salt mordant does not ‘bite’ the plates aggressively, nor create toxic fumes while active.

 

Friedhard Kiekeben in www.nontoxicprint.com (The Magic of Electro-Chemical Etching, page 4 of 7) explains the process: “The new method is akin to creating a liquid battery. The etching battery consists of two types of metal that act as the charged poles of a battery – anode and cathode – and an electrolyte medium (here the salt solution) that transmits electric charge and allows the metal ions from the steel plate to migrate.”

 

In my own words I would describe the process like this:  Copper sulphate acts as one pole, the steel plate acts as another (like anode + cathode) and the salt solution is the medium, where the charge travels (not to be taken as an accurate scientific description please!). The result is a fast and clean bite (10 –14 min for s solid line, tones bite in 3 min steps).

 

Etching grounds = Resists

 

The acrylic varnishes (resists) in their liquid/wet state are water-soluble. The single molecules are called monomers. In the process of drying and hardening these molecules form chains with each other called polymers. Once this has happened the varnish is hard, like plastic, and cannot be washed off with water alone anymore. It is the perfect resist to protect the steel plate from the biting mordant. It will only come off in a stripping solution (warm water and soda crystals). Understanding the chemistry of the acrylic resist grounds opens up more creative possibilities.

 

‘Johnson’s Klear’ floor varnish works well as a ground. It is a household floor varnish intended for wooden floors.

 

Other products are specifically made for acrylic resist etching. ‘Z-Acrylic’ (USA) produces a liquid hard resist and a stop-out varnish. The Swiss company  ‘Lascaux’ has created a whole ARE series, consisting of liquid hard.- and soft resist, spray  varnish, plate backing varnish, remover/stripping solution, wash ground, and more.

 

Additionally it is also possible to make your own grounds (‘Golden GAC 200’ (acrylic binder) and ‘Graphic Chemical’ water-based relief printing ink, ‘Speedball’ screen filler, Carborundum, sand, sugar, washing-up liquid, water—to name some ingredients).

 

The classic etching tools can be used to draw into the grounds. Textures can be imprinted into the soft ground. Wash grounds create unpredictable structures on the plates. The creative potential is huge and much is left to explore.

 

I hope this brief outline of the ARE process (this is really only the beginning) has been informative and has created interest in the technique as much for experienced etchers as for someone new to etching.

 

This system is a cheaper and healthier alternative for create etching plates and is very suitable for small workshops or private ‘home’ studios.

 

All my research and my experiments are based on the publications of : Friedhard Kiekeben in www.nontoxic.com

 

Robert Adam and Carol Robertson‘s book: ‘Intaglio’, The complete safety-first system for creative printmaking, Thames & Hudson, 2007;

 

Alfons Bytautas from Edinburgh Printmakers shared recipes and other information.

 

Tracy Hill, Senior Technician at  UCLAN Preston shared advice with me on equipment.

 

I would like to thank all of them.

 

 

heike roesel, june 2010

 

 

 

 

aquatints

 

 

The aim of the test was to create a very velvet deep black tone Acrylic Resist Aquatint

 

Aquatints are resist grounds that produce tonal ranges on etching plates on the plate.

 

Spraying acrylic varnish (resist) onto the plate will create the tonal ranges, like traditional rosin powder aquatint.

 

In traditional etching an ‘open bite area’ on a steel plate will bite rough, exposing the grains in the steel. These areas hold ink and give a limited tonal range. Zinc always requires an aquatint for any tonal variation.

 

In acrylic resist etching the alternative biting mordant (copper sulphate / salt solution) bites the steel (or zinc) very ‘clean’. Ink will only hold at the edge of a bitten area, very much like zinc does in trad. etching. Therefore a spray aquatint needs to be applied to the steel or zinc plate to create a variety of tones.

 

The aim here is to produce a rough plate surface that will hold ink. The steel plate has a natural plate tone, which looks like a light aquatint tone. This should be taken into account when planning a tonal range. Zinc plates have a much smoother grain and un-bitten the surface will not hold any ink.

 

An ordinary spray -can (car spray, hobby craft spray) will produce a coarse – dot- resist. The spray -‘dots’ will protect the metal – like a resist – and the mordant will bite in between these dots.

 

The better quality sprays that are used by artists (for example ‘Montana’ range), produces a finer spray and therefore a finer texture of ‘dots’.

 

A spray gun with a compressor (see notes on spray guns below) allows adjustment of the quantity and dot-size of the spray varnish (resist) that hits the plate. This can produce dots of a coarse nature to a very fine dot- structure, resulting in coarser textured or a finer aquatint.

 

Method:

 

Acrylic resist aquatints tend to show a dotted structure. The aquatints have been described  as dull and a very deep velvet tone being difficult to achieve.

 

After many experiment, we have developed a simple way of creating tones that do not show a dotted texture. We simply apply the aquatint spray resist up to 10 times per aquatint (spray rounds). The resist we use is a diluted solution of Lascaux Aquatint Spray Resist. We think the resist dots are of a semi- permeable nature and start to break-up in the biting process.

 

In practical that means, that the first sprayed dots will start to dis-integrate during the biting process and are replaced by new ones. These new dots will sit in different positions on the plate surface allowing the whole ares to be bitte , but crucially, not at the same time and not for the same amount of time. This creates a ‘sandpaper-like’ structure on the plate and is ideal for holding ink.

 

With this method, two principles run parallel to each other:

 

Firstly: The number of these ‘spray rounds’ defines the texture of the tones gained. More spray rounds result in a less grained aquatint texture. By re-applying the aquatint spray in between the biting steps, the broken down previous dots are replaced. The new dots occupy a different spot. It is crucial most spots are exposed to the biting mordant at different times and for a different lengths of time. It is a random process. Here a plate surface is created that feels almost like sandpaper, rough and uneven, holding the ink evenly. Secondly: The lengths of the overall biting times define the lightness/darkness of the tones, just like in traditional step biting.

 

The structure of the dots create the plate surface. This structure depends on the size and the amount of these dots.The aim is to give the plate a good ‘rough’ tooth to hold the desired amount of ink.

 

For a very dense tone, with no little white dots appearing in the print, re-spray the plate between the biting steps (up to 10 times). The amount of ‘spray rounds’ defines the texture the plate will gain. Make sure, only a fine layer of resist dots hits the plate in each spray round.

 

The length of the biting times in between the spray rounds determines the darkness of the tone: (light = 1-5 min., medium = 5–14 min., dark = 14 – 28 min. overall biting times). But bear in mind that steel has a very light tone already, unless the plate has been sanded done very much (10 min, 6oo grade wet&dry paper). Steel plates don’t start from a white tone. Zinc does.

 

Spraying needs practising. Less is more, try to lay a very fine cover about 40 – 50% coverage of the plate area. The Metal needs to show through. The plate can by laid down on  newsprint, or stood up against the back of the spray booth.

 

Uniform aquatint: Start spraying outside the plate area on the paper, moving across the plate onto the paper and than back again further down to cover the next section, till the whole plate is covered. That way it is possible to see how much spray comes out of the gun and hits the plate. Let dry for 2 minutes, turn the plate 90 degree and repeat. Let dry for a few minutes before stopping out or biting.

 

Because the spray gun is also a very flexible drawing tool, it is worth mentioning the countless creative possibilities that lay in using a spray aquatint as resist. The gun allows the artist to ‘draw’ on the plate, creating variations in the way the plate surface is covered.

 

Spray – aquatinting needs to be applied for any wash-grounds (= permeable grounds- see further down).

 

Aquatint grounds, Spray booth, Spray guns and Compressor:

 

Lascaux aquatint spray, de-ionised water or tap water, in dilution of 3:1 (3 parts ground to 1 part of water) used with a Badger 250-2 and a ‘Z-budget kit baby compressor from the airbrush company, Lancing, Sussex, BN15 8UF, Tel: 01903 875960, www.airbrushes.com;

 

Also tried: spray gun ‘Premi Air 35’, that is available with the compressor (Z-Budget Kit for £ 109.99). But this air brush clogs up easily and needs cleaning as soon as the spraying is done.

 

The Badger 250-2 is a very simple spray gun, that does not easily block, and if it does (after hours left in it’s jar), it’s easy to clean: simply use a needle and push through the dried ground. But it never blocked while spraying. I leave the mixed ground in the glass jar attached to the gun for hours while I bite and re-spray the plate. The spray gun is easy to clean.

 

The Premi-Air is a much more complicated spray gun, and clogs up quite easily. The ground seems to be drying in the nozzle while spraying. I damaged nozzle and needle when trying to un-block both and had to replace them. I also find the dots are almost to small and cover to much of the plate surface.

 

For a Spray booth a large cardboard box is a good starting point. It’s important to wear a mask (for toxic vapours) when spraying to avoid breathing in this very fine dust.

 

Tracy Hill and Emma Gregory, printmaking technicians at the University of Central Lancashire have researched and tested a number of different recipes. Their results are published in Printmaking Today, Autumn 2011, and on their blog: http://nontoxicintaglio.tumblr.com/

 

Many thanks also to Tania Ruthland, who pointed me into the direction of the small sized affordable compressor.