Name: Mady Lacaprucia and McKenzie Stuetzel Date: 11/28/17
Room Temperature: 66 Degrees Fahrenheit Humidity, ect: Not humid
Experiment Title: Test 10 – Silkscreen Mesh 200
Experiment Goal: To see how a higher mesh count and a thicker layer of emulsion will affect our print.
Plate Preparation: We first printed out a new positive using different bitmap settings. We learned that when bitmapping for silkscreen, you should find the correct frequency by taking the mesh count and dividing by 5. Therefore, since we are using a silkscreen 200 mesh, the frequency we used was 40. We also learned that 22.5 is an ideal angle to use, as it is halfway between 0 and 45 and will create less of a moiré effect.
Two weeks prior to exposing, we had coated a screen using a single layer of emulsion, and our last experiment used a two layer coat of emulsion. This week we coated the screen heavily with three coats of emulsion, because we are trying to figure out if the thickness of the emulsion is the reason for our gray prints. We exposed it for five minutes and then washed out the extra emulsion. After exposing the mesh, we attached it to our plate using a sheet of double-tack adhesive.
Print A: Two coats of emulsion and no shellac
Print B: Three heavy coats of emulsion with shellac
Printing: We printed these plates using Gamblin Bone Black ink mixed with burnt plate oil on Hahnemuhle Copper Warm White on a Praga press with a pusher and a catcher.
Conclusions: We used two different plates during this test; plate A has no shellac sprayed on it after the 2 coats of emulsion, and plate B has a layer of shellac sprayed on it after 3 heavy coats of emulsion. The problem we found is that if you don’t use shellac the image starts to peel away during the inking process, which is why it is important to spray shellac. This seals the emulsion so it doesn’t get destroyed during the printing and inking processes. Also with plate A we noticed that without shellac and light layers of emulsion that we get a gray tone over the entire print because the ink stays in the texture of the mesh. Whereas in Plate B, we have much cleaner whites from the thicker emulsion and the spray shellac protection.
Next test proposal: As our results have been worse since switching to this new method, for our next test we are going to return to the original plate-building process of first applying the mesh to plate and then applying the emulsion, rather than applying the emulsion to an unattached piece of mesh. However, the double-tack adhesive sheets have been great at keeping the mesh on the plate, so we will continue to use them as our adhesive instead of acrylic paint.