Polymer plates like Toyobo or Solarplate are expensive, but there is much cheaper polymer material, called ImagOn, that can produce much the same look.

ImagOn is light sensitive polymer film, sold in rolls. The film can be laminated (commonly with water) on many types of base materials (copper, zinc, aluminium, plexiglass) and then used like other polymer plates. The film is very thin compared to polymer plates – a reason why its ability to form grooves deep enough for holding the printing ink (needed to render the darkest tones) has been sometimes questioned.

We laminate ImagOn film on aluminium offset plates. The plates come disposed from a printing house, but after cleaning they are perfect for carrying the ImagOn film. There is a top Mylar protective layer on ImagOn, it can be left on or ripped off before the exposure – the resulting image will vary by contrast and tone scale depending on which choice was used.

The blue ImagOn film can be laminated on many materials – we have been using aluminium plates, which can be easily cut to different sizes after lamination.

A laminated ImagOn plate can be handled and exposed the same way as the thicker polymer plate, but it seems to be much more sensitive to UV, needing shorter exposures. It is developed in 1% sodium carbonate solution for 2 minutes, with the top layer removed.

We started testing the material with our system, finding first a decent exposure for the screen (we were using the same aquatint screen as previously for the Toyobo plate). Our most promising screen exposures were around 10 seconds.

An aquatint screen exposure test. At 5 seconds exposure the plate is under exposed and shows an area of open bite (ink will not hold there), 10 seconds looks pretty good, and 15 seconds and more are overexposed (no black any more).

Next we made a test print where a 101-step tablet was exposed on the plate after the screen exposure. Both exposures were 10 seconds, with the top Mylar left on. After processing the plate we noticed that the exposure for the stepwedge could have been even shorter in order to shift the tones higher, towards highlights (a positive process: less exposure darkens the image). But it is a pain to get constant repeatable exposures shorter than 10 secs with our uv unit, so we decided to continue with these exposures. The important thing is to be able to find both maximum black and paper white from the test strip, so that the curve can be constructed.

A screen exposure and 101-step wedge exposed on ImagOn, both exposures 10 seconds. After processing and printing the plate (left) the tone compensating curve was derived.

After a number of test prints we came to conclusion that it’s not easy (for us anyway) to pull prints from ImagOn with good photographic tonality. Besides, we had a very busy study module with students on this topic, with so little time for printing…

Saara Leppäkoski: ImagOn Gravure.

The next thing to try will be exposing ImagOn through screened films, with no separate screen exposure … actually done that already – but more later…