Nontoxic Printmaking, Safe Painting & Printed Art

Aquatint Screen                             

Elizabeth Dove

An Overview
If you intend on working with drawings and photopolymer printmaking films like ImagOn, then you need an aquatint screen to provide a dot pattern. First the polymer plate is exposed to the aquatint screen to provide an overall rich black aquatint-like base, in preparation for a second exposure to a drawing or continuous tone positive.

This Aquatint Screen perfectly simulates the random dot of a fine aquatint. After these two exposures the polymer plate is developed, dried, and printed with traditional inks in the intaglio manner.

ELIZABETH DOVE has been making Aquatint Screens for more than ten years, and contributes the following information.

Background to the development of the Aquatint Screen

Making intaglio prints from polymer plates is a recent and exciting contribution to traditional etching processes. Photographs and hand drawn imagery can be transformed into an intaglio print without the use of toxic materials or acids. Although this represents a major change to conventional etching processes, many of the traditional rules for plate making are still relevant when working with polymer films - for instance, the need for a dot pattern or texture in the image areas of the etching plate. This texture or dot pattern on the polymer plate determines the quality of the finished print in much the same way that an etched aquatint dot, or a soft ground texture, determines the quality of a conventionally etched plate.

Ideally, an Aquatint Screen has:
  1. A dot pattern that is opaque to ultraviolet (U.V.) light
  2. Dots distributed in a fairly random pattern
  3. A dot frequency varying between 60% to 75% coverage (depending on the brand of photopolymer plate used)
  4. Dots small enough not to be noticed on the finished print, but large enough to hold a rich amount of ink to print a deep black
  5. Dots that vary somewhat in size and shape to echo the appearance of a conventionally sprayed or rosin aquatint
  6. A sturdy, durable transparent base material that does not fog or otherwise interfere with U.V. light exposure
  7. Been imaged using film or toner that does not stick to a photopolymer surface if the protective Mylar coating is removed from the plate prior to exposure

Use of the Aquatint Screen
The Aquatint Screen is used during the plate making stage to provide the necessary dot pattern in conjunction with the photographic or hand drawn positive. How do you establish the dot pattern on a polymer plate, specifically when working with a photopolymer printmaking film like ImagOn? A drawing or photograph can be turned into an etching by using an Aquatint Screen.

The Aquatint Screen is used for direct contact exposures to ImagOn photopolymer film. Each Aquatint Screen has an opaque dot structure.  Exposing this Aquatint Screen to an ImagOn plate will create an overall rich black aquatint-like base, in preparation for a second exposure to a drawing or photographic positive. First the ImagOn plate is exposed to the Aquatint Screen to provide a random dot pattern, then a second time to the image. After these two exposures the ImagOn plate is developed, dried, and printed with traditional inks in the intaglio manner. The process from exposure to print takes about 30 minutes.

Using the Aquatint Screen with Drawings

The intaglio mark making possibilities when working with the Aquatint Screen are numerous, ranging from subtle ink and tusche type washes to delicate hand drawn lines to bold expressive crayon drawings. All drawings and paintings must be on transparent or translucent material. All drawing or painting materials must be opaque to high intensity U.V. light.

This non-etched process presents a direct and painterly approach to creating intaglio prints. Graphite, gouache, acrylic, watercolor, watercolor pencils, lithographic-type wax pencils and crayons and tusche all work beautifully as drawing materials onto transparent acetate or frosted Mylar.

Using the Aquatint Screen with Photographs
Photographs can be transformed into intaglio prints when the Aquatint Screen is used as the base to create the dot pattern. Photographs can be reproduced from photocopies, digital, or darkroom positives. All photographic material must be positive, not negative. All photographic material must be on a transparent or translucent base and the image areas must be opaque to high intensity U.V. light.  

Note: If you are able to control the dot pattern either digitally or in the darkroom, you can create a halftone with an open dot in the blackest areas. If this open dot is about 60% to 70%, then you will not have to use the Aquatint Screen, as this halftone dot is sufficient to create the necessary dot pattern for your intaglio print.

Elizabeth Dove

hybrid print

The History of the Aquatint Screen
The history of the Elizabeth Dove Aquatint Screen involves several intriguing coincidences. This Aquatint Screen's distinctive dot pattern is derived from the original non-glare Asahi glass, produced in Japan until the devastating Kobe earthquake of 1995. Due to domestic restrictions on the use of hydrofluoric acid in Japan, non-glare glass was made using unique patterns that were rolled into the hot plate glass during manufacture to impart the non-glare texture. Coincidentally, this pattern was ideal for producing photographic halftones in the darkroom, perfectly suited to photo-intaglio work.

Non-glare glass has been used in a darkroom for decades as a contact dot screen to produce halftones from graphic arts (lith) film that are suitable for various photomechanical printmaking processes.

Cheaper than traditional contact dot screens, non-glare glass also offered an alternative to the mechanical dot of commercially produced dot screens. Since non-glare glass is almost exclusively manufactured using hydrofluoric acid, the dot patterns produced by the available non-glare glass companies were all very similar. Frosted Lexan and textured Mylars offered other slightly different options to the maker of halftones. By contrast, Asahi non-glare glass was quite different.

This Asahi glass was unique among non-glare options for darkroom work because its hot-rolled manufacture process established one side with a superb, random, variably sized fine dot structure that was embedded into photographic halftone but was invisible in an intaglio print. The opposite side of the glass produced an interesting bubble-dot pattern that was larger and very visible in a print, and could be selected for special tasks and creative applications.

The Asahi non-glare glass was produced in Kobe for a domestic Japanese market. By chance, several crates of this glass were sold to retailers in Western Canada in the early 1990s. Even more by chance, some of this glass ended up in Peace River, Alberta, then the home of printmaker and researcher KEITH HOWARD. Always looking for alternative materials for his photoetching, Howard tested this glass and quickly recognized its ability to produce exceptional halftones for photo-intaglio work. He promoted the Asahi glass through his teaching, workshops and books across North America and Europe, even though shipping a single sheet of it without breakage was nearly impossible.

I joined Keith Howard as a researcher in Peace River in 1995, the same year as the significant Kobe earthquake. One of my research interests was perfecting an aquatint dot screen for use with DuPont's Riston (later retailed by DuPont as ImagOn). Attempts at making Aquatint Screens on an inkjet or laser printers were frustrating; the printed dot on the transparency was too delicate, the screens had no longevity, and the dots from these sources were typically very shallow and did not create a suitably rich print. Various physical approaches were tried: spraying, sanding, blasting. However nothing came close to the refinement of an optical dot produced photographically.

Working in the darkroom, I developed a method using large sheets of Asahi glass to produce an Aquatint Screen where I cut exposure time into six segments. With each fractional exposure I moved the position of the Asahi glass a tiny amount, thereby distributing the dots in even finer and more random numbers than a single sheet of glass would do alone. I used Fuji graphic arts lith film and conventional lith developer to produce an opaque dot. These were time consuming and delicate screens to make.

In the aftermath of the Kobe earthquake disaster in 1995, the Asahi glass factory was relocated to Indonesia and this particular hot rolled manufacturing process was eliminated in favor of the conventional approach using hydrofluoric acid. For the time being this did not directly affect Keith's research as he had stockpiled several crates of glass, but printmakers and photographers new to these processes could not acquire a sheet of Asahi any longer to make their own halftones in the darkroom. In much the same way that I had been making the Aquatint Screens - by shifting the position of the glass six times during exposure - I began to produce a soft-dot version of this screen pattern and called it a Halftone Screen that would replace the lost Asahi glass. The Halftone Screen was also made from Fuji graphic arts lith film. Unlike the Halftone Screen it was developed in photographic paper developer to produce a soft, semi-translucent dot for use as a contact dot screen in a darkroom to produce halftones for photoetching. An artist working in a printmaking studio with a Halftone Screen and an Aquatint Screen could produce fine photographic and autographic images on photopolymer plates.

Keith Howard's workshop teaching schedule increased from 1995-1998 as more and more printmakers heard about his research work and the opportunities of these newer intaglio methods.  During this period DuPont became interested in the burgeoning fine arts market for its photopolymer products, and began marketing its Riston film as ImagOn in roll sizes (100 sq. ft. rather than 1000 sq. ft.) that artists could utilize and afford. Since the Aquatint Screen was so critical to many ImagOn processes, I began receiving orders from all over North America, Europe and Australia for my screens.

By 1998 I recognized that I could not keep up with the demand by making these in the same laborious way any longer, and collaborated with a service bureau to digitize the Aquatint Screen and produce the film on an imagesetter. I produced a flawless 20 x 24 Aquatint Screen using my darkroom method. This screen was then drum scanned, and its digital file sent to be imaged by a laser onto conventional silver-based graphic arts film. The advantages of this approach were efficiency, predictability, a sturdier film base than my darkroom film, and the opportunity to increase scale to 35 x 42 (the maximum the imagesetter could do). The disadvantage was the need to add a secondary dot pattern (from a stochastic screen) and an increase in the manufacturing cost by about 30%. It seemed worth it to be able to capture this now extinct Asahi glass pattern and make it available to printmakers anywhere. From 1998 to 2007 the screens continued to be produced in this fashion.

The next challenge has appeared, in that commercial service bureaus are discontinuing their use of imagesetters as the commercial print world converts to direct-to-plate technology and no longer needs film based output. For the near future, I have stockpiled Aquatint Screens and should be able to supply demand for a year or two, at which point the research will begin again!

Transparencies and Artwork
The Intaglio Type or photopolymer printing process involves the use of transparent artwork; as in silkscreen printing these are positive; one needs to bear in mind that the image reverses from plate to print.

Transparencies can be made using a laser printer, inkjet printer,
photocopier, or by hand.

It is important to ensure that the transparency is as opaque as possible in order to obtain a good plate.

Transparencies can also be sandwiched together to create hybrid assemblies of images.
Doubling up two copies can increase t
he density of the black areas.

Unless a halftone dot is present most transparencies will not give good reproduction of grey tones or black areas. For this reason a special random dot aquatint screen (such as the Dove screen) has been developed to ensure that Intaglio Type prints yield the full tonal spectrum and rich blacks.

For more information and methods click on the following links:

Beginners Compendium   Intaglio Manual    Solarplate

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