Name: Mady Lacaprucia and McKenzie Stuetzel Date: 12/5/17
Room Temperature: 66 Degrees Fahrenheit Humidity, ect: Not humid
Experiment Title: Test 12 – Extra Layer of Emulsion to Obtain Whites
Experiment Goal: Our goal is to do exactly what we did in Test 11, but to put an extra layer of emulsion on our plate in an attempt to get the whites of our image to print whiter.
Plate Preparation: Using the same bitmapped positive from the last experiment, we exposed our plate for the usual five minutes and removed the excess emulsion under the sink. We are again experiencing a loss of details in our plate due to too much emulsion wiping away.
A note on emulsion thickness: As we have discovered, thicker emulsion produces better whites. Yet it is not exactly the number of coats applied that is important, but rather the thickness of the emulsion, which can be discerned based on color. Here is a photo of what a good amount of thickness looks like in the darkroom; however, keep in mind that all darkroom lighting will be slightly different, and yours may not look quite the same. Another good rule to go by is that if you can still feel the tooth of the mesh through the emulsion, then the emulsion is not thick enough, as the mesh will hold ink.
After exposing the image and washing out the excess emulsion the screen should have the a dark purple look to it:
Printing and Conclusions:
We printed the plate on a Brand press with a pusher and sizing catcher set to a medium pressure. We used Hahnemuhle Copper Etching paper and Gamblin Bone Black ink mixed with 00 burnt plate oil.
With the thicker coating of emulsion, we were able to achieve whiter whites than our previous test. However, a lot of detail got lost during the process of washing out the emulsion. We are discovering that it is very important to make sure that the emulsion has adequate drying time before exposing the plate. Not enough drying time before exposure is most likely the reason why we have been losing parts of our image.