The process outlined below was devised during a workshop demonstration. We had an extra processed gelatin step tablet on copper and etched it in a single bath of ferric chloride. Instead of controlling the humidity and waiting hours for the gelatin to dry the plate was placed on a hot plate to dry. After twenty-five minutes the plate was cooled to room temperature and placed in one ferric chloride etching bath. I was surprised it worked and have been using this method with fairly consistant results ever since. If a film positive and tissue are prepared in advance it can take less than two hours to process a photogravure plate. The process outlined below was created using Dragon Gravure Tissue and an Epson Printer. It is a simple outline. There is a considerable amount of information between the steps.
- Create a film profile limited to a maximum density of 1.4.
- Print a digital 21 step tablet on your film of choice.
- Sensitize Dragon Tissue in a 4% potassium dichromate solution chilled to 45 degrees for 75 seconds.
- Use equal tone and aquatint exposures.
- Degrease the copper.
- Place the degreased copper plate in distilled water chilled to 45 degrees.
- Slide the exposed tissue face side up into the tray with the copper.
- Flip the tissue over and position it over the copper. Remove the copper and tissue from the bath at a gentle angle. I use a thick glass sheet positioned on an overturned tray in my my sink as a surface for laminating the gelatin tissue and the copper. The surface you squeegee on should be close to the temperature of your mating bath.
- Blot the backing paper and wait 75 seconds.
- Immerse the plate into 115 degree development water. Wait two minutes before peeling the tissue.
- After 4-8 minutes of minutes of agitation and hosing the clearing is complete.
- Place the plate in a 50% tray of isopropyl alcohol bath for 2 minutes. Remove the plate from the alcohol and flood with 75% isopropyl. Agitate the plate in hand. Flood the plate twice within 45 seconds.
- Dry the plate as evenly as you can. Rock the plate and watch the alcohol closely. Modify your technique to make the alcohol evaporate as evenly as possible.
- Allow the plate to rest with air circulation for twenty minutes.
- Mask the plate.
- After twenty-five minutes of total drying place the plate on a hot plate heated to 120 F for twenty-five minutes.
- After twenty-five minutes move the plate to a room temperature surface.
- As soon as the plate has cooled to room temperature etch in 40.3 ferric chloride.
- Proof.
- Create a profile. Make plates - Make prints.
- Review the photogravure reference page for trouble shooting and more information.
Tips:
- Look closely at everything.
- If you have problems run through the entire process with very bright lights on.
- Use a head magnifier.
- If something is not working properly repeating what you did will not make it work.
- Experiment - read - study. Do not believe everything you read.
- Don’t sneak up on things. Test and test again.