Researcher’s Name: Olivia Arau McSweeney, Pace Knowles-Donnelly, Margo Temple, 2019
Abstract: For this project, we experimented with using glue as stop out. At Zea Mays, we strive to use the safest, most non-toxic materials for our printmaking practices. Research shows that some acrylics are toxic to humans and the environment– they also happen to be a material commonly found in stopout.
“What looks like the gentle formation of a paint film through evaporation of water is, on closer inspection, a very powerful chemical reaction that begins when the acrylic paint has left the can, and water evaporates, effectively cooling the near invisible, high-energy process. . . Any such reaction is likely to produce unwanted byproducts, ‘SVOCs’, –– contained in the mix or airborne –– and acrylic polymer paints and mediums are no exception to this rule, and in fact the reactivity of free monomeric radicals entering the working atmosphere, entering the body through skin contact, or by inhalation is of increasing medical interest. There evidence that active acrylic monomers can impair the ability for self-repair in human tissue, due to suspected interactions with DNA mechanisms” (Friedhard Kiekeben, nontoxicprint.com).
However, acrylic material is difficult to stop using all together because most synthetic glues are made with acrylic. Though their chemical structure is different, research has not extended to the dangers of this particular substance. We have found that natural glue (animal or plant based) is the only guaranteed alternative that does not have acrylic in it. In this experiment, we used both synthetic and natural glues with varying results.
Elmer’s School Glue
Elmer’s Natural School Glue Stick
In this experiment we used five different kinds of glue: PVA, Glue Sticks, Elmer’s Glue, Nori Paste and Elmer’s Green Gluestick
Glue sticks worked very well as stop out. For the higher etch times it started to dissolve slightly but not a noticeable amount. In the second row from the bottom, Liz experimented with using a brush and water to paint the glue on. This technique was less successful in stopping out the acid.
PVA was also extremely successful in its stopout abilities. It is perhaps the most toxic however because it is ‘PolyVinyl Acrylic’ but its different from conventional stop out. If it is applied thickly it can take a significant amount of time to dry, but the result is no different than if applied an even thin coat. It did take several rounds of scrubbing with Estisol 242 (VCA) to completely remove the glue after etching.
Nori Paste is traditionally used as an adhesive for delicate paper, such as in bookbinding and chine-colle. This glue was the least successful of the group of adhesives. It was able to hold up for a 1 minute etch and started to breakdown for a 5 minute etch even though the 1 minute etch was reapplied after every etch. The 12 and 20 minute etches were almost completely dissolved by the ferric chloride. Even when applied after every etch for the 1 minute etch and in heavier thicknesses, there were many spaces that were left unprotected and inevitably etched. This is not a very reliable stop out but there is great potential for experimental image making. It is also not an acrylic based glue.
Elmer’s School Glue:
Elmer’s School Glue was a great candidate for stopout. It held up when etched for up to 20 minutes without dissolving in the acid. We experimented with using water to thin the glue so it could be more easily brushed on and it did not significantly break down.
Elmer’s Green Gluestick:
We found out that Elmer’s sold a ‘natural’ glue stick which we were very excited to try out! Unfortunately, the longer etch times broke down the glue similarly to the nori paste. It did create some beautiful texture, but it is perhaps not the best substitute for a reliable stopout. We were not able to find the MDMS Sheet for the Green Gluestick, but based on the way it is marketed and the way the acid broke it down, we are assuming that it is a water based glue.
How To: Using Glue as Stop Out
Step 1:Degrease Plate
First, degrease the plates before application, to ensure proper adhesion of the image. After degreasing, rinse with hot water (to speed up water evaporation) and dry with clean newsprint.
-Bon Ami mixed with water to form a paste (if a polish is needed)
Make image on your plate and use the glue to stop out the values you would like to etch first. For areas that are more heavily saturated with glue, allow to dry for 12-15 minutes and for less about 5 minutes.
Step 3: Etch your plate as you normally would and print it accordingly.