作田　富幸　銅版画作品　Tomiyuki Sakuta   Printmaking gallery  vol.1 (1984~2023)  (2024~)
 

My Non-Toxic Plate-Making Technique
While working on the Arcimbolto series, I suffered from severe headaches during the long black varnishing process. Since then, I have considered the health aspects of my work. As someone currently involved in education, I am particularly concerned with not passing on harmful plate-making techniques to the next generation. Below, I will describe my approach to non-toxicity and how to deal with it.

In some parts of Europe and America, non-toxicity is already commonplace, and even within the same country, approaches can vary greatly depending on the educational institution and teacher. In Japan, too, practices vary greatly depending on the instructor's approach, whether in universities, educational institutions, or public or private workshops. This is likely due to the lax national regulations on solvent use. Currently, the most advanced example of non-toxic practices in Japan is probably the Kitayama Copperplate Engraving Studio in Kyoto (http://www.hanga.info/). Their website is a very valuable site as it details their completely non-toxic practices. Furthermore, please refer to the website of Naoji Ishiyama, an artist currently residing in Finland (http://www.kolumbus.fi/naoji/), where his own practices are described.

When I visited the studio of Naoji Ishiyama, a senior figure in the non-toxic field, and spoke with him about various things, he said that quality was more important than the non-toxic aspect. At the time, I was determined to master non-toxic techniques and objected to his words, but the more I researched since then, the more I understand. While I won't go into detail here, all copperplate engraving techniques are now possible based on non-toxic methods. These include aquatint (applying water-soluble resin with an airbrush), liftground, softground, and so on. I've tried various white balance-like techniques based on available information, but I still feel the quality is lower compared to classical techniques. (Of course, you can't know anything just by trying everything...) And most importantly, what is the purpose of non-toxicity? If there are no environmental or health problems, there is no necessity to deliberately pursue lower quality.

So, what is a non-toxic (non-toxic plate-making method)? And what is its purpose?

The two main reasons are environmental considerations and the impact on human health.

From an environmental perspective, the traditional, classical copperplate engraving method is perfectly fine. In fact, the currently used non-toxic-based methods may even be more problematic. For example, water-soluble ink. This ink can be washed away with a little soap and water, eliminating the need for traditional petroleum-based solvents, which is very convenient. The acrylic ink is then discharged into the wastewater. Traditional oil-based ink cannot be washed away with water, so it is washed with a solvent, absorbed into rags, and incinerated as combustible waste. Clearly, this is more environmentally friendly.

Next, regarding the impact on human health, the most harmful aspect of the classical plate-making method is the use of nitric acid as the etching solution. The extreme toxicity of nitric acid is evident from past cases, so we would like to ask many workshops to refrain from using it. (However, there are exceptions if there is perfect ventilation or if it is used outdoors.) Using ferric chloride would suffice. I've been fortunate enough to never have experience with nitric acid in plate making, and I don't understand why anyone would want to use it—the unique taste of the lines, the texture of aquatint, etc. However, judging from the experiences of friends and glimpses of the symptoms of past artists, I consider myself lucky that I started with ferric chloride when I learned copperplate engraving at university. If you're working in your own studio indefinitely, then it's fine as long as it harms your own body...

Next is the issue of solvents. Nowadays, no one uses thinner to clean ground or ink. I use it on extremely limited occasions, such as when removing toner powder, but even when using just a few drops, I feel it's necessary to ensure proper ventilation and do it outdoors. Similarly, I use benzine and white gasoline to create special textures by mixing them with markers, but when using them in a studio, you must ensure adequate ventilation in the room or at least adequate airflow to avoid harming many other users. However, I don't take a stance of completely eliminating organic solvents used in such special techniques.

What I really want to emphasize is what I'm about to write. Regarding ligroin, its use as a solvent should be avoided because the toluene it contains is highly toxic as an organic solvent. And this is actually easy to do. If you (or your workshop) are using ligroin to strip ground, or to clean ink and oily substances, I recommend stopping immediately and using the following method. Until now (March 2012), I found EcoWash, a vegetable oil-based cleaner, very useful for stripping oily substances, but it seems that it has recently stopped being imported from Switzerland. As a substitute, Desolv-it, which is made from orange peel extract and imported from the USA, is a good option. 1 gallon (3785ml) costs 6930 yen (http://item.rakuten.co.jp/interiortool/desolvit-1g/). However, it is a bit expensive. To use, apply a small amount of Desolv-it to the oily surface, wipe it with a tissue, and while it's still slightly slippery without completely wiping or drying, sprinkle neutral detergent (mixed with water in a 1:1 ratio) over it and brush. This will completely wash away the oily residue with water. (However, too much remaining oily residue might be environmentally problematic...) For removing ground, scrubbing with a toothbrush will dissolve it more easily. Please try this cleaning method! For small pieces, you can clean them with just one tissue!

For ground application, it's best to heat and melt solid ground in a warmer before applying. Spreading it evenly with a rubber roller should prevent mistakes. However, from experience, the heating and spreading method seems to result in weaker adhesion than the pour-and-slide method. Pinholes are also more likely to form. However, dipping the plate in etching solution before application and then washing it with soy sauce significantly increases ground adhesion, making it comparable to the pour-and-slide method. Next, you can add oil soot or other methods as you like. Because it slightly roughens the plate surface like frosted glass, it can be restored by polishing with metal polish (like Pikaru) when removing the ground after etching. The method of pouring liquid ground (which most instructors probably teach) does not eliminate the harmful effects of ligroin. As an aside, since warmers for printmaking are expensive, I recommend using a "crystal warmer," a household appliance used for keeping soup warm, which can be purchased for under 3000 yen on sites like Yahoo! Auctions.

Next, regarding varnishing. Traditionally, the common method is to dissolve black varnish in ligroin and apply it to the cover surface. However, this process requires inhaling ligroin at very close range throughout the varnishing process. It is an extremely dangerous procedure. If you absolutely insist on this method, and if you are working alone in a workshop, wearing an organic solvent mask is essential. However, breathing with a mask on is quite difficult. Ligroin evaporates quickly, and the applied black varnish dries quickly, making it perhaps the easiest to handle. However, is this the only way to cover the problem? Actually, there are several other options, and they are all harmless to humans. The following methods should be used depending on the situation.

1. Using Water-Based Ground (Bunbodo brand)

Although originally developed as a water-based ground, I use it as a stop varnish. Its properties—resisting corrosion but being water-soluble—make it ideal for single-pass aquatint etching. With some ingenuity, it's possible to wipe off the corrosion with a tissue after the first etching without washing with water, and then re-varnish. It's completely harmless to humans and easy to apply.

2. Using Magic Marker (Solution)

For covering incorrect lines, pinholes, and plate marks in ground drawing, Magic Marker (solution) is a convenient and recommended option. It's also effective for covering during aquatint, and since it doesn't wash off with water, it's suitable for gradual etching and varnishing. For removal, use fuel alcohol or wax remover. However, due to the high sensitivity of the dye, fingers can become completely black if gloves are not worn, and the etching lines may also be slightly stained black. Furthermore, while methanol, found in magic marker solutions and alcohol, is significantly less dangerous than toluene, inhaling large amounts is still harmful. Magic markers are convenient, but somewhat harmful. The extent to which this is acceptable is left to individual judgment.

3. Using dried black varnish while dissolving it with odorless brush cleaner

Odorless brush cleaner evaporates slowly, and the idea is to dissolve the hardened black varnish with it. While odorless brush cleaner is said to have reduced organic solvent content compared to conventional brush cleaners, it doesn't contain zero organic solvents, and the amount isn't indicated, making it difficult to judge its harmfulness or harmlessness. Moreover, its odorless nature might make it even more dangerous depending on one's perspective. I only use this method when I absolutely need to use black varnish. This is only when I'm creating a deep black surface by reapplying rosin after each etching of aquatint. Because brush cleaner evaporates slowly, the black varnish also flows gradually, making it easier to cover than when using ligroin. After application, heating it for a few minutes with a warmer solidifies it without any problems.

Currently, non-toxic water-based stop varnishes have several drawbacks, such as cracking if applied in excess, requiring a special solution for removal, and being difficult to remove.

Incidentally, the use of water-based grounds such as floor wax still doesn't match the quality of classic oil-based grounds, and my method of applying oil-based solid grounds is harmless to the human body, so there's no necessity to use water-based grounds in the first place.

However, this method is particularly effective in copperplate engraving. It may be difficult to implement in other types of printing.

As I mentioned at the beginning, I'm not particularly interested in perfectly non-toxic methods. Simply put, I just dislike ligroin. Also, if you're looking for a mysterious, alchemical, and potentially harmful atmosphere in copperplate engraving, please ignore my opinion.

January 2012

Tomiyuki Sakuta