A new type of photo-etching process

A new type of photo-etching process

Developed by Keith Howard,
using a new film from DuPont.

General Processing Guide

Introduction

The Intaglio-type represents a new family of printmaking techniques developed by Keith Howard, that allows a great variety of image making possibilities. Intaglio-type techniques utilize ImagOn in conjunction with conventional etching presses and traditional etching inks. ImagOn can be used for all photo-generated imagery from high quality halftones to computer generated images, even simple photocopies, to achieve the highest quality photo-intaglio print. Painting and drawing techniques can also be achieved by working with drafting Mylar. A large range of subtle ink and gouache washes can also easily be transformed into print. Intaglio-type techniques with ImagOn represent a departure from traditional intaglio plate making, and offer the printmaker unparalleled image-making capability without compromising health, safety or the environment.

Studio Lighting for Using ImagOn Film

Keep ImagOn away from Ultra Violet (UV) light sources and direct sunlight. Low ambient lighting can be used without exposing ImagOn 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 for the plate under incandescent light. After ImagOn 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.

Materials Needed

ImagOn

Plant spray mist bottle

Isopropyl rubbing alcohol (70% solution)

Intaglio plate (plastic wood or metal)

320 Grit sandpaper

Blank newsprint paper

Extra sharp trimming knife

Etching press and blankets

Soda Ash (sodium carbonate)

Gram scale or teaspoon

Liter or quart measuring container

Two photo developing trays

Conventional etching inks and paper

Dish washing sponge

Neoprene rubber gloves and eye protection

1.Plate Preparation

Cut the plate to your intended image size before adhering ImagOn. If ImagOn 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. Use a 50% water and alcohol solution to clean plastic plates.

2.ImagOn Preparation Prior to Lamination

Cut ImagOn slightly larger than the size of the plate. Handle ImagOn carefully to avoid dimples in the film. The inside peel back layer has a soft feel somewhat like plastic wrap; the outside Mylar layer has a stiffer feel similar to cellophane. Remove the inside peel back layer. Place the ImagOn with the outside Mylar down onto a smooth etching press bed. Use a plant spray mist bottle to spritz the exposed surface of the ImagOn 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 the 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 art work, including sunlight and photo flood lights, however, it is difficult to obtain consistent results. 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 or use ?? teaspoons of soda ash to make 1 quart. 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 five minutes in direct sunlight is also a good alternative. ImagOn has fully hardened when its blue color disappears.

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 ImagOn 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.

Questions & Ordering Information

ImagOn is manufactured by DuPont and distributed through Praga Industries. For more information about using ImagOn or to place an order, call 800-844-9421 or contact the Praga World Wide Web site at http://www.praga.com

The information set forth herein is based on data believed to be reliable, but the DuPont Company makes no warranties express or implied as to its accuracy and assumes no liability arising out of use by others. This publication is not to be taken as a license to operate under, or recommendation to
infringe, any patent.

Compiled by Keith Howard; 7/96 e-mail howard@agt.net

Non-toxic Printmaking Page;
http://www.mtsu.edu/~art/printmaking/non_toxic.html

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