A technical dictionary of printmaking, André Béguin.
Studio Lighting for Using ImagOn TM
Film
Keep ImagOn TM away from Ultra Violet (UV) light sources and direct
sunlight. Low ambient lighting can be used without exposing ImagOn TM
provided that the preparation process is carried out in less than 30
minutes. Cover windows with a red or yellow plastic translucent
shower curtain or prepare ImagOn TM for the plate under incandescent
light. After ImagOn TM is developed, there are no light
restrictions.
Safe Handling
As with all
photopolymers,
avoid direct contact with film by wearing rubber gloves. Do not heat
above room temperature. When working with chemicals, it is always
recommended to wear eye protection. See
Safe
Handling Guide for more
detail.
1. Plate Preparation
Cut the plate to your intended image size before applying ImagOn TM
film. If film is to be laminated onto a copper or steel plate, it
must be thoroughly cleaned by sanding with 320 grit wet and dry
sandpaper and wiped with a dry clean cloth. Take care to ensure that
finger prints are not transferred to the surface of the copper plate.
Thoroughly clean any other type of metal plate with Comet or Ajax
Cleanser and kitchen pot scrubber. Rinse thoroughly with plenty of
water before drying. Use a 50% water and alcohol solution to clean
plastic.
2.
ImagOnTM
Preparation Prior to Lamination
Cut ImagOnTM
slightly larger than the size of the plate. Handle ImagOn carefully
and avoid putting any pressure on the rolls. It will leave
impressions in the film. The inside peel back layer is soft and
cloudy in appearance; the outside Mylar® layer is stiffer and
clear. Remove the inside peel back layer first. Place ImagOn with the
outside Mylar® down onto a smooth etching press bed. Use a water
spray mist bottle to wet the exposed surface of the ImagOn film
liberally with a solution of one part 70% isopropyl rubbing alcohol
and three parts water. If the relative humidity is high, ImagOn will
adhere without this solution.
3. Laminating ImagOn to the
Plate
Hold the plate upside down about 2 inches above and parallel to the
dampened ImagOn and drop it onto the film surface. Trim the edges of
the ImagOn with a sharp cutter. Set the pressure of the press
slightly tighter than required to print a fine aquatint. Lay a clean
sheet of newsprint on top of the plate before lowering etching
blankets. Run through the press at about one foot every 12 seconds.
Carefully trim the laminated ImagOn flush with the plate edges,
cutting in a way that will not cause the edges of the film to lift
away from the plate.
4. Exposing ImagOn
When exposing artwork to the plate, the emulsion side or
photopositive of the artwork is facing down. Various Ultra Violet
(UV) light sources can be used to expose ImagOn to the artwork,
including sunlight and photo flood lights. To obtain consistency
however, absolute exposure control is important to optimize image
results, therefore, a professional exposure unit or plate burner with
a built in light integrator and point light source is
recommended. A good vacuum in an exposure unit produces the best contact between
the halftone film positive or art work and ImagOn. A 400W Mercury Vapor lamp
positioned about 14" away from a vacuum frame requires exposure times of 15
seconds to 1 1/2 minutes depending upon the artwork used. A 1000 W Clear Metal
Halide lamp in a non-commercial unit requires from 3 to 20 seconds.
It is essential to make step tests to determine the correct exposure for the
various Intaglio-type techniques. Once "optimum" exposure times are determined,
post them on the side of the exposure unit for reference.
5. ImagOn Developing Solution
Use only the anhydrous variety of soda ash powder (sodium carbonate) available from
swimming pool chemical supply companies. Add 10 grams of soda ash powder
(approximately one level teaspoon) to about 4 teaspoons of hot water and stir until
dissolved. Add room temperature water to make a volume of 1 liter. The working
temperature of the developing solution should be about 65-70°F.
Pour into a photo developing tray.
6. Developing ImagOn
Remove the Mylar® layer from the ImagOn, then place the plate into the
developing solution. Wearing gloves, rub with a dish-washing sponge for about
2 minutes. The unexposed areas of ImagOn will wash away in the developer, leaving
valleys and grooves in the remaining ImagOn characteristic of an intaglio plate.
Knowing precisely when the image is developed is a matter of experience based on
visual inspection and the tactile feel of ImagOn. Rinse the plate under running
water, squeegee off remaining water, then leave to dry naturally in a vertical
position.
7. Harden the ImagOn Plate
ImagOn must be light-hardened using UV light before inking and printing. The
time necessary varies, but is at least double the exposure time for a halftone
image. The minimum light-hardening time for the 400 W Mercury Vapor exposure unit is
90 seconds; for the 1000W Metal Halide exposure unit, 20 seconds. Two to 5 minutes
in direct sunlight is also a good alternative.
8. Final Edge Preparation
To add a crisp edge to the image, bevel the edges of the ImagOn on the plate with
320 grit sand paper and a small block of wood or an electric finishing sander.
Hold the sanding block or finishing sander at a 45° angle.
9. The ImagOn plate is now ready to be printed in the conventional Intaglio manner.
10. Removal of ImagOn
After the print has been editioned, the plate can be completely reclaimed by
cleaning off the etching ink with vegetable oil, then leaving the plate to soak
overnight in old ImagOn developer. When the ImagOnTM lifts from the plate, rinse it
in water. A final cleaning can be done with Comet or Ajax Cleanser. A 4% soda ash
solution takes from 30 minutes to 2 hours to remove ImagOn.