[Student Projects, Printmaking]

Printmaking

Background

Intaglio is one of many different types of printmaking. It involves producing a design beneath the surface of a plate, covering the plate in ink, and running the inked plate through a press. Etching is one way to produce an image beneath the surface. Etching is the use of acid to make lines into the surface of the plate. The plate is usually a form of metal. Most popular and the one I chose is copper. Copper produces a nice print in the end and is not all that hard to deal with overall. Etching has its roots in both Italy and Germany because the process was developed about the same time in both countries at the start of the sixteenth century (Chamberlain 11).

Materials

rubbing alcohol

cotton balls

a metal plate around 1/16 inch thick

Vaseline

conc. nitric acid

water

engraving needle

pan suitable for etching

a fade-resistant pigment

plate oil

mortar and pestle

paper

printing press

paper towels

spray bottle for water

hand soap

gloves

Procedure

In order to make a print, the printmaker needs to follow a certain procedure in order to be successful. The artist should start with a piece of metal about 1/16 of an inch thick. Copper and zinc are two prime examples used. The edges of the metal plate should be filed into smooth edges in order to prevent tearing of the paper in the printing process.The plate needs to be cleaned from grease in order for a ground to be laid. Rubbing alcohol can be used to clean the plate. After the plate is cleaned, an acid resistant ground needs to be applied. Stop- out varnish is one way. This can be made by making a solution of resin in alcohol. One ratio used is 1 part Rosin to 3 parts alcohol (Peterdi 113). This proves difficult for some, including me. I used Vaseline to coat my plate. An etching needle is used to engrave the image to be etched. I used woodworking tools to make my image. There are many options for the etching needle including: knitting needles, nails, ice picks, and any other sharp pointed object.

After the desired image is produced, the acid resist must be cleared from the area. Only the area to be etched is to be cleared. After the plate is engraved and ready to be etched, an acid bath must be prepared. Many different acids can be used. I chose to use a Dutch Mordant because it makes the finest lines without bubbling. One recipe for Dutch Mordant is 9 parts water saturated with potassium chlorate to 1 part hydrochloric acid (Peterdi 145). Another is for nitric acid. The recipe is 3 parts water to 1 part conc. nitric acid (Heller 215).There are many others. After a particular line is etched and is to be no longer etched, an acid resist should be place over it if there is still etching to be done.

Once the plate is completed, the printing must be done. An ink, paper, and a press are now necessary. An ink can be made with several different pigments as long as the pigment used is fade resistant. Some popular ones are bone black, vine black, and lamp black. The pigment is then added to plate oil, a form of linseed oil. With a mortar and pestle, the oil and pigment should be mixed to form the ink. The ink is rubbed into the grooves of the plate. The ink is then removed from the plate leaving ink in the groves only. The paper needs to be slightly and uniformly damp. Once paper and ink are ready, the press is now needed. The paper can now be placed on the plate and run through the press. The prints are numbered as they are produced in the tradition of printmaking. They should decrease in clarity as the print number increases. In my case, all the prints were blurred. None of them turned out well. I determined that I under etched my plate. It caused the ink to smear. The images were too smeared to scan into my web page. I printed 3 prints to no avail. I photographed print 2 to scan into the web page to show the smearing effect.

Observations

Printmaking is more difficult than it looks. Carving takes time and skill. Straight and curved lines both prove difficult to produce. The needle slides all over the plate leaving behind unwanted images.Copper should also be easily etched. I found out that it is not all that easy. The Dutch Mordant I tried in the beginning did not etch the copper. It cleaned the surface and stopped. In this mordant I used 5M HCl in the recipe 9 parts potassium chlorate saturated water to 1 part acid. In the next mordant I used a 3:1 HCl solution in the same recipe. There was still no etching. After two failed attempts at using Dutch Mordant, I decided to try nitric acid. Concentrated nitric acid reacted quickly and violently. A 3:1 acid solution reacted more slowly and less violently. A 2:1 solution reacted in the middle of the concentrated and 3:1 solution.

I decided to use nitric acid in etching my plate. I used 300ml of water and 150 ml of nitric acid in my mordant. In 6 minutes a good reaction had occurred. Some etching had taken place.The reaction produces a frothy blue-green color. The reaction is bubbly and turns all the mordant blue-green. After 30 minutes, I removed the plate. Etching was obvious at this point.

The ink was the next challenge. I mixed Prussian blue and Bone black in a mortar. I added linseed oil because I did not have plate oil. I slowly added the oil to the pigments until a thick and gummy mixture resulted. It had the linseed oil odor to tell the amount of oil added. I rolled the ink on with a brayer and it went on thick no matter the amount of ink I started with on the plate. I then wiped the plate clean hoping ink would remain in the etched portion. It was hard to wipe and took a while. After wiping, I pressed the damp paper onto the inked plate. I rolled the cleaned brayer over the paper. I removed the paper to finish my smeared mess. My prints were big messes.

Conclusions

To sum up the information provided in the observations, the information is arranged in tables to make understanding the process a little easier.

Dutch Mordant Results

5M HCl	saturated water	20 minutes	no etching
3:1 HCl	saturated water	32 minutes	no etching

Nitric Results

conc. nitric acid	added to Cu metal	5 minutes	violent reaction
2:3 nitric acid	added to Cu metal	5 minutes	small reaction
1:2 nitric acid	added to Cu metal	5 minutes	no reaction

conc. nitric acid	added to Cu metal	10 minutes	still a violent reaction
2:3 nitric acid	added to Cu metal	10 minutes	now is strong
1:2 nitric acid	added to Cu metal	10 minutes	now reacting

With the given charts, the recommended solution is either 1:2 or 2:3. The conc. nitric reacts much too vigorously and gives off a lot of gas. It is not useful in printmaking. The Dutch mordant is not useful either. I found no reaction in two different concentrations. When a good reaction is occurring there is some bubbling and a blue-green color is produced. The color comes from the oxidation of the copper metal.

Prints Conclusions

Print 1	no obvious picture, light print
Print 2	more smeared and darker than 1
Print 3	even darker than 2

I have determined that the plate must be etched rather deep. The paper has to have the perfect dampness. The ink has to be pressed at a certain weight. The first plate I used the least amount of ink and the driest paper. The second plate I used more ink and the wettest paper. The third plate I used the middle amount of both ink and dampness. My methods did not work out very well. I ran the paper under the faucet and stacked the between paper towels instead of other ways. I would recommend spraying a thin film of water onto the paper shortly before printing. I used the brayer to apply pressure instead of a press. I also recommend a press. The ink is messy and stains. Be careful and have your hand soap handy. I also recommend wearing gloves in the inking and printing processes.

Aftermath

Printmaking proved a challenge. I began my project with the hopes of printing images with different depths. Once I actually started in the lab, my plan failed. It became more of an effort to etch the plate. Which acid will eat into copper became the emphasis of my project. I spent most of my project time etching the plate. Once I finally got an etched surface, it was finished. The reaction stopped and the plate would not etch any deeper. Therefore, my prints were blurred and dark. I was not able to produce an etch deep enough to hold the ink completely below the surface of the plate. This resulted in the smearing. I learned that chemistry is not an exact art. It takes time and experimentation to produce results. Things do not always go as planned.

Christy Rochelle '98