I prepared the sheet with an ‘Aquatint’ ground of silkscreen fabric. This was stuck to the plate using the Gel medium. Due to the size of the plate, as the fabric was laid over it I used a stiff piece of card to squeegee along the fabric, to remove any air pockets or ridges. I wanted the surface to be as uniform and smooth as possible. When it was dry, I trimmed the fabric to the plate edge.
I chose silk screen fabric as I have been using this on cardboard collograph plates and it holds the ink very well to produce the darkest tone.
The emulsion was applied in quite a thick layer, using a piece of stiff card as a squeegee.
Removing the tape gutter was also awkward, and revealed more wet emulsion. So the hair dryer was used
again! To transport the plate I made a light proof envelope with 2 sheets of black Canson Paper.
Again I used ezyscreen A4 artwork transparency film to create my film positive. I decided to use a
thicker margin around the design, as positioning the film positive onto the plate was still proving to be tricky, I lay the transparency onto the plate, while it is still in its light proof envelope, while being in a dark room. Then I only have to quickly take the plate and transparency out, when I'm in front of the exposure unit, and place it under the glass. Practice makes perfect!
I decided that 1.5 minutes would be my exposure time, as this appeared to be the most appropriate exposure time, as trialled in the first experiment.
As I had applied the emulsion in a thick layer, wash out did take a long time. A brush was used to encourage the unexposed emulsion to wash off, however it also meant that the whole emulsion layer stayed wet and soft, and the potential to damage it was high. There is a portion of a line that was removed by the brushing action. I changed the wash out water three times, and kept it at a warm temperature, (which was measured as equal parts of boiling water and cold water. Total ‘bucket chemistry’ was in play here!)
Once I had washed out as much as possible, and was satisfied that I couldn’t remove any more, the reverse of the plate was wiped and it was placed back under the light to harden the emulsion. (Tip: don’t turn the UV light off, as you need to let it cool down completely before you can turn it back on again.)
This time I decided to try inking and printing the plate without a shellac coating. I think the resulting image (below) printed well without this step. I am pleased with the outcome.
I will continue to use the silkscreen fabric rather than the courser tarlatan to create the ‘Aquatint’ ground.
The next trial plates will have a thinner layer of emulsion applied, and no gutter. My reason for this is that a thick layer isn’t necessary when applied over the silkscreen fabric, and a quicker washout is preferable.
I don’t think I will need to shellac in future, as this plate held up well to the inking and printing process and the clean up of the oil based ink was very easy, using Dis-olve, a citrus based (non turps) cleaner.
I am enjoying the mark making that occurs by ‘accident’ when the plate is being created. There are portions of the process that I am creating ‘blind’ due to the plate becoming light sensitive, and also the vagaries of the emulsion as it dries. I am also pushing a product to be used in a manner that it wasn’t made for, Diazo photo emulsion is used to coat silkscreens, in a thin layer, that would dry quickly and
I am still using hard edged images, as per my current body of work. I will endeavour to trial an image that has softer edges, and finer detail to see where this technique can develop to.
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