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Finally I have finished printing the second lot of six valves. These six plates had to be inked twice as after the first day of inking the resulting print was not satisfactory. The pressure of the press was equal but it seemed that it needed to be a little tighter. Also, as another factor, the plates may have been rubbed too much, so the result was quite light.
The second day of inking the plates I made sure that Paul Atkins (Print Making Resource’s manager) double checked the plates before inking and he also put more pressure on the press. This time the press was so tight that two technicians had to turn the wheel. The print came out well. Finlay Taylor (MA Print Making tutor) was there and he was very complementary of the result. Paul Atkins has requested an edition to be part of their archive. I’ll probably do this during the assessment week.
I have now photographed the two sheets of valves and taken them to the framers. I have chosen a hand made and painted white box frame with no mount board so the print will be floating. This style is quite minimal, modern and extremely good quality, which is something I was looking to achieve as again I am trying to encapsulate the industrial era feeling of the images and make a parallel with our contemporary times.
Elements of the frame
Frame detail
Floating mount detail
After all this work I am really looking forward to seeing them hang on the wall.
I have been attempting to print six plates featuring my images of valves in one piece of Somerset satin. My attempts can be seen in blogs part1 and part2. I tried to solve it by using different wetness of paper but that didn’t seem to be the problem and also by packing the bed with print paper the same size as my output print to increase the pressure. Evaluating the print, there seems to be a lack of contact between the plate and the paper. The brand of paper used, soaking time, and pressure settings of the press are all factors that will greatly affect how the print will look. A considerable amount of pressure is required to get good prints using a fine aquatint screen. A solution to even the amount of pressure from the printing press could be to cut irregular concentric shape out of print paper to prop up the problematic areas.
So this time the paper was soaked for 3 hours but very well blotted so there were no wet patches. I actually moved the printing to a different press. This printing press was quite tight for the size of the paper, the edges where slightly hanging out of the bed and I had to trim my registration sheet to fit it. Still, I wanted to see if the pressure of this press was working on my plates before doing all the irregular concentric shape padding. I run the press again and…unfortunately there were still a few white patches which meant that this press although not as worn out it was still a bit worn out and the pressure wasn’t even or I just didn’t add enough pressure. I’ll have to try again.
Different stages of inking the Toyobo Printight Solar Plate (KM73):
First day of inking the first six plates. I made an acrylic sheet registration plate, marking with a pen the outline of the six plates in their correct position and the paper size.
The fine stochastic screens I used create a very delicate aquatint, especially in the soft highlights. I used Charbonnel black etching ink
55981, is a universal supple black, viscous but easier to wipe than others. I applied the ink initially with a square bit of card spreading an even thin layer. Then I used cheesecloth with a twisting motion of wrist, lightly grinding the ink into the tooth of plate and at the same time wiping off the excess of ink and smoothing it out. I followed this with a tissue paper wipe to control and smoothen highlights. Once the plate was cleanly wiped I took a clean piece of cheesecloth and lightly dragged it over it in a random pattern. This is called retroussage, it cleans up and smoothens remaining micro-clumps of ink in a random fashion.
Finally, I wiped the edges with flannel rag changing the angle so it moves the ink toward the back of the plate. When the rag came back relatively clean, I flipped the plate face-down onto clean newsprint and wiped the back with the rag too. Then I double-checked and rewiped the edges. This process took about 40 minutes per plate. Luckily I had some help from Claire Alonge, who made the whole process much more bearable 
Towards the end of the day the plates were ready to print. The paper, Somerset satin 410gms, had been soaking for the last forty minutes and it was time to place the plates in the right position on the bed of the press, following the marks of the registration plate underneath. The paper was then blotted and put on top of the plates facing down and covered with two sheets of tissue paper with the blankets on top. I run the press with some help as it was a big heavy wheel due to the pressure needed to print, trying to move through the press consistently and not too quickly (if you stop once the press is in motion you may leave a heavy roller mark on the print).
Once it was through I had a look at the print. Unfortunately it hadn’t printed properly. It looked like some parts of some of the plates didn’t print; there were white patches near the center of the two columns, especially in the two last plates. It may have been due to the paper being too wet or not wet enough, it could be due to the pressure of the printer. However, I was not certain of which.
What I am trying to achieve presents a challenge. Printing six plates at the same time on a single sheet of paper puts six different pressure points on the single sheet, the tension applied to the paper when it goes through the printing press is irregular and to achieve uniformity is very difficult.
Disappointing after a days work but next week I’ll do it all again.
Today after spending many hours in the UV exposure unit room I managed to expose the Solar plates for my photo intaglio process.
The printer at college wasn’t able to do more than one of my positives as the acrylic film kept getting stuck on the printer. I was working with the technician and we tried several times with a variation of settings but the same kept happening. I wasted a couple of days because of this mishap- not good.
Yesterday I got my new positives made in an Imagesetter by commercial printers. An imagesetter is a high resolution output device that can transfer electronic text and graphics directly to film, plates, or photo-sensitive paper. It uses a laser and a dedicated raster image processor (RIP) and is usually Postscript compatible. Unlike the resolution on a home printer, which is probably between 300 – 600 dots per inch (dpi), the resolution on a typical imagesetter is 1270 or 2540 dpi with a maximum dpi of 4000.
The very first time I did a successful plate, my positive was from a inkjet printer and the plate was exposed to an Aquatint Screen during 15 light units, then another 15 light units exposure of the positive and 3 min development.
Because my new positives where made in an imagesetter they are different to the previous one – the positive created with an inkjet lets some UV light through the denser black dots whilst the positive from an imagesetter has dead-black opaque dots - I was told I would not need to use an Aquatint Screen. I exposed one plate for 15 light units to the positive of my image and then developed it for 3 minutes (following the settings of my first successful plate).
But it didn’t work, what should have happened is that the opaque dots of my image positive should have stopped the light going through giving me a less rich black. A rich black means a deep tooth on the polymer and many of these mean that the polymer may come out of the metal plate all together. But it is also truth that when developed too much polymer can came off the darker areas of the plate. As I developed my plate as long as the previous one I thought that I should try using the Aquatint Screen in the next exposure.
So, today I exposed the Solar Plates for 15 light units each to an Aquatint Screen, which is an 80% stochastic screen covered with tiny dots of random sizes, shapes and distribution. The dots are small enough not to be noticed on the finished print. Aquatint Screens are used to prepare Solarplates for intaglio printing. The plates are first exposed to the screen so they are partially hardened. When they are exposed to the art work and developed, areas that were blocked from the light will still have enough photopolymer to hold the ink when it is applied, eliminating open areas or deep grooves that hold too much ink. Allowing the resulting print to show a wide variety of tones including rich, deep blacks.
I found some information about the history of Aquatint screens, artist Elisabeth Dove, who based her study in the research of printing with Ashahi glass by Keith Howard, developed her own aquatint screens and commercialised them in the US.
As advice, I read that if you want to increase the richness of blacks, darken your image and retain more detail, you should reduce the exposure time. Alternatively, if you have problems with grooves holding too much ink, or you want to lighten your image, or if there is too much polymer washing away (this is what happened the very first time I did a plate) the thing to do is to increase the exposure times.
As an experiment I did increase the exposure times for one of the Solar plates to 30 light units and didn’t use the Aquatint screen previously. Unfortunately the polymer still washed away from the plate, so I guess that the increasing exposure would only work to modify the lightness of your image. Due to the price of every Solar plate (£10) I decided to stop experimenting and stick with the exposure of Aquatint screen for 15 l.u. plus another 15 l.u. for the positive and then, once developed for 3 minutes and dried, I hardened them by exposing them to UV light for 30 l.u. I will let them dry for a week before inking them.
Toyobo Printight Solar Plate (KM73)
I got the first stochastic positive printed from the inkjet printer Epson Stylus Pro 4800 at collage using Wasatch RIP program. For the settings I choose the Epx800Promic- Han German paper setting in the printer driver at 1440 dpi. My first positive was successfully printed. I could now use it to make my first plate. I went onto exposing the Toyobo Solar plate.
Steps for the exposure:
- Firstly it was exposed in the UV light unit to an aquatint screen for 15 light units.
- Secondly it was exposed to the positive for another 15 lu.
- To develop the plate it was washed for 3 minutes and then blotted with newsprint paper to stop the etching
- Once dried under the fans for a few minutes it was exposed again during 30 lu for hardening.
I applied a thin layer of ink (F66- is a soft medium black) to the plate with a roller and then blotted it with Tarlatan (cheesecloth) until all the excess ink was removed. To finish the inking of the plate I used a technique called retroussage:”The method of bringing ink up from incised lines (or dots) in an intaglio plate; dragging a soft cloth across the ink-filled lines prior to printing to spread the ink to the adjacent areas and to render certain passages darker and richer”.
To print it the paper (Somerset satin) needed to be soaked for 30 minutes and subsequently put between blotting paper and pressed with a rubber roller to remove the excess moisture. It was then ready to be printed. Laying the printing press bed with tissue in order not to dirty it, then the plate is placed and on top the soaked paper good side down and some more tissue and the blankets on top for pressure. The pressure on the printing press indicated 3/9. Finally it is passed through the press and dried afterward between blotting paper.
I am happy with the result of this process, the dot of the stochastic positive has given the print a very fine quality that resembles old grainy photographs. Now that I have had this result I have confidence on following this method of printing, which means that I don’t need to research Lambda printing any further.
Valve 1. Solar plate print
Valve 1 detail. Solar plate print
I got some good results with the photopolymer plates. I bought a Toyobo Printight Solar Plate (KM73) which allows high resolution positives to be transferred to it. Because of this I was told that I could use a different way of printing the positives, called stochastic printing. [Stochastic is a mathematical term that means random, having to do with random variable/s involving probability or chance]. It differs from the conventional printing in the modulation. Conventional Printing is AM (amplitude modulation) and Stochastic printing is FM (frequency modulation)
- Amplitude Modulation. In printing, used to refer to conventional halftone printing techniques in which dots of various sizes (amplitude) are used to reproduce the tones and colors of a continuous tone image, with large dots used to reproduce the darker areas and smaller dots to reproduce the lighter areas.
- Frequency modulation. Used in printing to refer to stochastic printing techniques in which the number of dots, and sometimes their size as well, is changed to reproduce the different tones and colours in a continuous tone image, with relatively more, closely spaced dots used to reproduce dark areas and relatively fewer, more widely spaced dots used to reproduce light areas.
(information from ED NewPage and education)
So, I am going to try to produce this positives at collage although I heard that it maybe a little difficult as a highly developed program is needed in order to use complex algorithms to place the dots more or less often as required in order to reproduce the image with no determinable pattern. If the ripping program -raster image processor- Wasatch (which is the one we have at collage) can’t handle working with the inkjet printer in this manner then I’ll have to go to a commercial establishment to get it done. One more thing to think about is that although this process (FM) will give finer detail than the conventional method (AM) also it is quite unforgiving and imperfections will be more visible sometimes showing too much detail.
Finally I have a big print of my picture. After a few test strips I printed this picture size 51x51cm I used a filter gradient number 3 and 30 seconds of exposure at f/8. Using the zone system and accounting for reciprocity failure meant that the picture had very good tonality. As a personal taste I wanted to make the contrast a little “punchier” so considering the distance in between the enlarger and the paper I used filter gradient 3. The quality was quite good but at the same time I think that I would like to use other films apart from Rolley 50 iso.
