This technique is best used with either a line drawing, similar to a Hard-Ground etching or to a halftone image. Some textured polycarbonate films such as True-Grain can also be used to simulate the halftone dot structure necessary for the success of this technique.

Because IimgOn Ultra is think enough to make a non-etch intaglio print it needs to be thinned if it is to be used as an etch resist. After it is thinned the ImagOn plate is exposed to the halftone image then developed and finally etched in a ferric chloride or Edinburgh Etch bath.

Do not to expose plate to excess light at any during the entire procedure

1. Prepare the copper plate with 600 grit sandpaper and laminate the ImagOn film
2. Prepare a 10 gm developing solution.
3. Set timer for 7 minutes

4. Remove the surface layer of Mylar from the ImagOn plate

5. Still develop the film for 7 minutes. (This will thin the film so that the ferric chioride can reach the copper during the etching cycle.)

6. Put on rubber gloves. Remove the plate from the developer and place it under room temperature running water.
7. Rinse plate under room temperature water until all ImagOn residue is removed. Gently rub with soft sponge until all loose residue is completely removed. At this stage it will be difficult to detect the presence of any ImagOn on the plate, as it should be very thin.
8. Remove plate from water and spritz with vinegar. This will stop the development. Very gently rub the vinegar into the film
9. Pat dry with paper towel.
10. Heat dry for 2 or 3 minutes
11. With a soft cloth rub a small amount of baby powder into the surface of the thinned Imagon plate. This will prevent anything from sticking to the Imagon emulsion during exposure.
12. Expose plate to halftone positive or line drawing

13. Still develop for 2 minutes plus 15 sec. hand development with soft sponge

14. Rinse with room temperature running water
15. Spritz with vinegar
16. Rinse with water and heat dry.
17. Cover the back of the plate with plastic packing tape to protect it from the corrosive action of the ferric chloride.
18. Hang the plate into the ferric chloride or Edinburgh Etch tank for 5 minutes
19. Pull out after 5 mins. and inspect the surface of the plate for areas that did not etch. Areas that did not etch will remain a light bluish color. Areas that etched will be copper in color.
20. For those areas that may not have etched brush soda as developer into these area for about 15 sec. Wash and place into the ferric chloride for an additional 5 minutes.
21. Inspect plate again for areas that may not be etching. You can only re-develop a few times before you compromise the film resist.
22. Etch the plate in the ferric for 20 - 30 minutes then remove, rinse, and check the depth of the bite. I strongly recommend using Akua Color water-based intaglio inks for both proofmg and editioning the plate. If you use the Akua Color Water-Based Intaglio ink to proof the plate you can see if the plate has sufficiently etched. If the plate has not etched sufficientiy wash the Akua Color off the plate with soapy water and re-etch the plate.
23. Fresh ferric chloride can etch a good black in about 30 minutes. The older the ferric the longer it will take to etch. Make a step-test plate to determine the optimum etching times.

My advice is to leave the Imagon emulsion on the plate, after etching it, and complete printing the edition. Only after you have completed the edition remove the ImagOn emulsion and re-print the plate. Now compare the prints. if you have successfully etched the plate then each plate will look identical. if not, detail or tone will be lost when the ImagOn emulsion is removed.