What I have written below is a very basic, overly simplified description of each step in the process of etching. As with any medium or technique, there are numerous nuances and alternative ways of arriving at the end point. However, as an introduction, I’ve elected to keep this section simple as an introduction to the medium. If you are going to practice this medium, please study and follow the necessary precautions for the materials/chemicals/tools you choose to use. There are a considerable number of hazards that could be present and pose a health risk. If health and saftey are of the utmost concern for you, there is a great community of ‘safe’ alternative methods available online. I have chosen to use a more traditional approach because it allows me to achieve the qualities of print that I desire.
+Preparing the Plate
Polishing the plate is a necessary step in the process as any mark or imperfection in the surface of the copper will potentially hold ink and create unintended artifacts in the print.
- Using a file or deburring tool, bevel the edges of the plate. This prevents sharp edges which when under pressure could puncture the paper and felt blankets (see printing).
- Degrease and clean the plate to remove any surface dirt or oils that might interfere with polishing the plate. A common degreasing agent is calcium carbonate and vinegar.
- Polish the plate to a mirror finish. In my case, I use a series of wet/dry sandpaper starting with 400 grit and working up to 2000. Steel wool, polishing compound and buffing wheels are used by some artists.
+ Grounding the Plate
With the plate polished, it is now time to coat the surface in a ground. The 'ground' is an acid resistant layer placed on the surface of the plate to protect the areas that etching is not intended. There are many types and ways to apply a ground to a plate. For this purpose, I will be describing a traditional hard ground which is a combination of wax and asphaltum.
- Degrease and clean the plate. This is necessary as any contamination of oils or dirt on the surface could cause poor adhesion of the ground. If this happens, the ground will lift off the plate during the etching and ruin the marks.
- Place the clean plate onto a hot plate and heat to 150-180 degrees. Overheating can 'burn' the ground and create porous holes in the surface which will create a 'foul bite' on the plate. Tests should be run to find a temperature for the ground and tools you are using.
- With the plate heated, roll and dab your ground onto the plate.
- Using a dedicated brayer, roll the ground onto the plate into an even coating.
- Remove from heat and allow to cool.
- Protect the back of the plate. I cover the back of the plate with packing tape as this will resist the etching solution and can be left on while running test prints. (This can be done with a number of methods/materials and at a variety of times. But I've included when/how I do it.)
- (Optional) Blacken the ground with candle by holding the plate upside down and using the flame to coat the ground in a fine layer of soot. This has the advantage of making the next step easier to see and also an help seal any holes in the ground.
+ Marking the Plate
This step is pretty simple and straightforward. More so than a lot of people want to make out. A steel needle glued into a wooden handle is the most common tool, however any instrument that will cleanly cut through the ground and down to the copper will work. I've used pencils, old fountain pens, nails and many other items lying around.
- Using an instrument or tool, draw into the ground surface applying just enough pressure to cut through the ground and down to the copper surface.
- As you draw into the ground, take care to clear away any loose particles so that they do not clog the marks when placed in the etching solution.
- Once the drawing or marks are completed, inspect to make sure all lines/marks are complete and expose the copper below and that any loose wax is removed.
+ Etching the Plate
Etching can be done with a number of solutions. Most common today is Ferric Chloride. Safety precautions should be taken and followed according to the hazards associated with the solution chosen. Similar to applying the ground, tests should be periodically run to find the etching times that achieve the desired results. This will need to be repeated from time to time as the solution will become spent and its results will change slowly over time. Also, keep in mind, temperature will play a considerable part in the effects of the etching results.
- With the plate marks completed, place it into the etching solution and start the timer.
- It is good practice to agitate the plate/bath to prevent particles from settling.
- When the etch time is complete, remove the plate and rinse in cool water to neutralize and stop the chemical reaction.
- With the plate now etched, it is time to remove the ground. This is done with mineral spirits.
+ Inking the Plate
The goal here is to simply fill the lines thoroughly and completely with ink.
- Mix and prepare your ink to the desired properties.
- Place plate onto hot plate and heat to the warmest temperature you can and still handle the plate comfortably. This helps the ink flow and saturate the etched marks.
- Roll or dab the ink onto the plate, covering it completely and thoroughly.
+ Wiping the Plate
Wiping the plate takes a lot of time, practice and technique, just like that of a brush stroke of a painter.
- Begin by wiping the plate with a dirty piece of tarlatan (an open weave muslin fabric). Using short, soft strokes to slowly remove the bulk of the surface ink.
- With the bulk of the ink removed and the image on the plate starting to show, use a fresher piece of tarlatan to remove further ink leaving a light layer of maybe about 30% still on the plate surface.
- Place a light dusting of calcium carbonate on the palm/meaty thumb portion of your hand and begin to gently hand wipe the remaining ink.
- With the surface wiped, use a piece of tarlatan to wipe and clean the beveled edges of the plate.
+ Printing the Plate
Printing of the plate is the final reward for all the hard work. Here you are rewarded with the results of all the previous steps. If you've done all your homework, run the proper test/trials and honed your skills/technique, then when you lift the print off the press, it should come out just how you imagined and intended.
- Prepare your chosen paper by soaking it and blot away excess water. (This softens the paper and makes it more receptive to the ink. Soak times and dampness are different for every paper and need to be tested to find the desired results)
- Set the press to the desired pressure. (Yep, you guessed it. You need to test what pressure to use as plate size, ink choice, paper type, and etching technique will all play a role in the results.)
- Place the plate onto the press bed face up.
- Place the prepared paper face down onto the plate.
- Cover the plate with the felt press blankets.
- Turn the presses crank and pull the print.
- Carefully remove the print from the bed/press taking care not to tear the print as the paper is still soft and fragile.
- Lay the print out to dry and cure. (Just like oil based inks, some print inks take weeks to fully cure.)