Last night I did a series of paper prints for Dylan and Amanda Bradway of DNA Galleries. Since I had a large series to do, I decided to post pictures and explanations to our Twitter feed of what I was doing. I thought the twitter tutorial was fun and got a lot of feedback, so I'll post it all here with some extended explanations. Hope you learn something!
Dylan and Amanda are creating a series of prints that highlight historic Oklahoma City buildings. I won't show you the entire series, but I will show you the process of just one image. (Look forward to seeing the rest!)
We begin with a high resolution, high contrast, black and white photo of the building in Adobe Photoshop:
By "bitmapping" the image, we successfully turn the image into a single color dot pattern:
After preparing the image on the computer, we print the image off on a velum transparency:
We take a blank screen with a mesh count of 305. The higher the mesh, the more detailed the image. It is basically the resolution of the image. (This is an example of a blank screen.)
We coat this screen with emulsion. Emulsion is basically a water soluable, light sensative latex. It seals the mesh completely, but because it's light sensative, allows the transparecy to block out the light in selected areas.
In our dark room we place the screen and transparency on an exposure unit, which basically looks like a tanning bed:
We take the screen and rinse it with water. All the negative space washes out with the water and we are left with a film postive of the image we want to print:
Once the water has dried, we take the screen and tape the edges off. Taping the edges allows us to cover the areas of mesh that aren't sealed with emulsion. A tape job well done will make the printing and cleaning process go smoothly.
Now we'll take the screen and clamp it onto the printing press. The print arm has what is called "Micro Registration." Each knob controls a directional movement. By adjusting these knobs, we can get the image lined up and locked. Once this is set, the image will hit in the exact spot each time.
For t-shirts we generally use plastisol ink, but since we are creating paper prints we will be using waterbased ink. I coat a squeegee with ink and prepare to print:
By pulling the squeegee across the screen at a consistent pressure and speed, I push the ink through the screen onto the paper. I lift the screen to look at the test print:
We pull a series of test prints in order to get acclaimated with the ink. You can see that by adjusting the speed and pressure, there are different consistencies in the print cleanliness. The prints will be done on nice thick paper, these test prints are on newsprint.
Once I'm satisfied with the print quality, I load on the nice paper and pull the whole series of prints. I try to run everything as consistently as possible. Paper prints and dot patterns can be very sensative to variables, by pulling the ink at the same speed and consistency I create almost perfect duplicates of the image.
Cheers to successful prints!
I do hope this was informative. We work really hard at our shop, and a lot of our customers don't know that screen printing is a hands on process. We don't outsource jobs, everything in our shop is printed by hand in our shop. Even using the automatic press requires an attention to detail.
Screen printing is a learned process and trade. It requires an ability to troubleshoot on the spot and a tolerance to getting your hands dirty. After 5 different series of prints, I left the shop tired but satisfied with my work at 3am and back at it at 9am. Work hard, and have a great day. It's beautiful outside, so smile lots today!