Tuesday, August 4, 2015

Teaching non-toxic etching using polymer based plate and vegetable oil inks

polymer plate intaglio and mix media prints by participant Muriel

Last weekend I made a journey to the community of Kenora, Ontario to deliver a two day intensive workshop in non-toxic etching. This was hosted by the Kenora Association for Community Living through their Arts Hub initiatve.
It was also the first time I have ever offered this particular technique publicly as a workshop.

The space we used is in a converted older house in a quiet neighbourhood of the town. There is a wonderful artist studio/residence across the street called Fragile Glass. 

Working in a space not really set up for printmaking proved a little bit of challenge. However I had given a workshop in this very same space back in 2012 and remembered the layout. I knew we would need specific areas in the space for each stage.

This time around there was a bit more working space due to some rearrangement by staff. I did have to improvise though and a downstairs washroom was adapted into a make-shift darkroom and the front entry porch become our print studio where there was a corner for the press, a large table for inking of the plates, a clothesline for hanging of work to dry and another table for papers. It was a bit tight so we could only have x number of persons really at any given time. We did manage to squeeze around 10 in for my demo on the Sunday morning. I find that showing first hand how a plate is made, inked and printed says a lot more than trying to read about it on a paper printout.

space in the printing porch was at a premium...everyone respected each other and a nice rhythm was established based on fairness of time allocation so everyone got a turn to produce several prints if they so chose

There were a few minor annoying glitches on the first day however things progressed much better on the second. 
Some issues with the new Kodak manufactured plates with regards to exposure and development times were thankfully resolved and just a couple of the small 4 x 5 inch plates didn't expose very well. The problem is that most of my knowledge prior to this workshop was with US manufactured plates sold under the brand name of Solar plate. The newer replacement plates are still marketed by Solar plate but there are some slight differences than the older formula plates mainly in term of exposure and developing (or wash out of the etch). The first thing I noticed is that the plates are a gold coloured emulsion. The older version was a bright pinkish orange coating. Plates are emulsion coated and this is fused onto a very thin steel plate. These are very sensitive to ultra-violet light. 
I use both a homemade exposure unit (blacklight tubes mounted inside a constructed wooden frame box) and also exposure outdoors to sunlight on days with very little clouds. 

The basis of using this method is to avoid using toxic solvents, acids and such that would require an artist to have barriers over skin, respiratory passages, eyes and also adequate ventilation.

My introduction to etching back in the mid to late 1970s had me coat a zinc or copper plate using a soft or hard ground. This material had to be melted onto the plate surface by setting a candle or propane torch flame underneath. Then came the challenge of getting an image onto the waxy coated surface. Once this was accomplished then I had to scribe into those delicate lines using a sharp etching needle. The plate was then immersed into a corrosive acid bath and allowed to etch for a specific time frame. If you wanted tonal and textural elements additional applications had to be made that included dusting the plates with a fine rosin powder to create and aquatint effect. It was a lot of work of covering areas of the plate, leaving some areas open to bite.
And finally was the ink application to the plate itself and the printing stages.

If you are interested in the viewing some of the traditional process here is a great 4 min duration video I found in You Tube that describes the process
I have found that using the polymer method can yield a good result and it helps speed the process up a bit with a few less steps than traditional. There is a bit of a learning curve involved however but once you have produced a few plates and produced successful prints it is a welcome change from the traditional method of etching that I mentioned.

The opaque black and/or grayscale artwork or grayscale photo based image is exposed to the plate for a determined length of time and then is developed in a tray of water using a scrubbing out technique. The plates can be used for both intaglio and also relief processes.

If one has a detailed piece of artwork or photo image with tonal gradations and wants their image to be produced as an intaglio (below the surface area that holds the ink) they would first pre-expose the plate to a very fine dot half-tone that is referred to as an aquatint screen. The plate is set onto a firm board with a cushion surface directly underneath the plate (bubblewrap, foam, etc..). The aquatint screen is set over top of the plate, a piece of plate glass is clamped tightly to the board to bring the half-tone screen and plate into very close contact. The shorter the exposure to a UV light source will yield a darker image, the longer an exposure the lighter the image will burn.
Artwork on film, inkjet transparency or direct application of media onto the plate surface is followed after the aquatint screen exposure.

I have found a good low relief plate surface can also be achieved with a direct exposure to the plate without the pre-exposed aquatint screen stage. Just remember anything that is black and opaque will be the area of the plate that will etch or wash out. For relief prints you want to use a longer exposure and have the areas that ink will not apply (below the surface). What I have done in the past is scan or take a high contrast photo of my artwork and revert it to a negative.

Several of the participants who attended had past experience with etching. 

Not only did the participants learn about creating artwork on film or inkjet transparency sheets but I demonstrated a few techniques for inking and printing the images once the plates were exposed, and the polymer surface was cured by post-exposing the plate again to UV light source.
These included 
  • the addition of linear/textural elements using an etching needle
  • combination intaglio with relief roll (ink wiped into lower etched areas followed by additional colour(s) rolled across the plate surface with brayers
  • producing a colour monoprint from separate thin acrylic plate followed by the overprint of the polymer etched plate
  • handmade oriental paper collage application (chine-collé)

Bill lifting his small etching with chine colle (the moment of reveal after running it through the press rollers).

Nestor Falls ON based artist Bill McFarlane and his first print off the plate with collage of light violet japanese paper

hanging works to dry on a makeshift indoor line
original painting created by Mureil and the black ink monochromatic print produced off polymer plate. We scanned here artwork first, converted it into grayscale and increased contrast so the yellow background would become a very faint gray tonal area.

this print originates from a collage of organic materials on card base. It was scanned and adjustments were made using photo-editing to give best contrast. The artist thought she might incorporate a bit of colour using watercolour once the print had dried.

printing studio in a small sunporch at Arts Hub in Kenora

Not only did the participants learn about creating artwork on film or inkjet transparency sheets but I demonstrated a few techniques for inking and printing the images once the plates were exposed, the polymer cured by post exposing the plate again to UV.
These included:
  • adding additional linear and textural elements using an etching needle
  • viscosity printing
  • relief roll
  • monoprint made from separate acrylic plate following by overprint of the metal etched plate

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