WHAT CAN BE FOUND IN THIS INFORMATIONAL MAGAZINE? VECTOR IMAGES VS. RASTER IMAGES DESIGNING AN IMAGE TYPES OF SCREENS EXPOSURE PROCESS TYPES OF INKS SUBSTRATES COLOR SEPERATION
11/2/15 SCREEN PRINTING FOR AMATEURS It’s not just squeegees and ink
The unofficial guide to screen printing for amateurs will help you through your journey of screen printing for the first time and tell you everything that you need to know to be successful.
PRINTING PRINCIPLE PRINTING PROCESS CLEAN UP PROCESS
BY: MIKE SACHS
VECTOR IMAGES VS. RASTER IMAGES
A Raster Image is an image that is made up of pixels. If you make it larger you the pixels get more noticeable and it isn’t very clean.
A Vector image is an image made mathematical calculations that form objects or lines. You can make it as large as you want and it will be sharp and clean.
Vector images are what we design in Adobe Illustrator!
Step by Step •
First you want to find an image that you want to trace on google
•
Once you have found your image you want to save it
•
Then you go into illustrator and place the image on a new art board
•
Go into layers and lock the layer with the image and create a new layer
•
Use the pen tool to trace the image
•
Use the anchor point tool to adjust curves
•
Adjust the fill color and then add a background color that will be the color of your shirt
That is the basics of designing an image on illustrator
DESIGNING AN IMAGE
Registration Marks must be added to the image above and below.
DIFFERENT TYPES OF SCREENS • Polyester Fabric (what we use) • Metal Mesh • Nylon • Metalized Polyester • Silk
The Screens in our lab: • 110 polyester • 230 polyester The number stands for threads per inch, so the 110 screen has 110 threads per inch. We use the different screens for different purposes too! Since the 110 has fewer threads, therefor wider spaces for ink to get through, we use a thicker ink, but we will get to that later.
EXPOSURE PROCESS Exposing is the first part of the printing process and must be done correctly for ones print to turn out nicely.
Step 1 of exposing in lining up your image on the screen! This is important so that your image is placed where you want on your shirt.
Step 2 is a fairly easy one as all you have to do is place it in the exposure machine squeegee side up and hit start after it is placed on the correct setting.
Step 3 of the exposure process is the clean out. • First you spray the squeegee side until you can start to see the outline of your image • Then you flip it to the print side and spray it for 20 seconds • Now that you have sprayed both sides you can turn the light on • All you do now is spray it out until all the emulsion is out of the image area
Make sure you get the registration marks!
TYPES OF INK There are 2 different types of ink that we use in class: • Plastisol • Alcohol based
• Alcohol based ink is a much thinner ink that air dries very quickly. • This ink is what we use to make window clings paired with the 230 screens.
• Plastisol is a thicker ink that needs heat to cure it. • It is the ink that we use for all of the shirts that we make and the ink that we use with the 110 screens.
SUBTRATES What is a substrate?
This includes: • T-shirts • Bags • Hats • Road Signs • Vehicles
A substrate is anything that you can print on!
COLOR SEPARATION Color separation is needed when you are doing a project with more than one screen.
The basics of it are as followed: • Turn everything of one color to black and everything else white • Print that sheet and repeat with the next color • It is very simple!
So you want to make this sweet lightning bolt logo. • First you turn the yellow to black • Then you turn the blue to white • Print it and switch the roles!
PRINTING PRINCIPLE The principle of printing is forcing ink through small holes in a screen to create an image on a substrate.
As you can see in this example the ink is pushed through the screen with the squeegee onto the paper to create the image.
PRINTING PROCESS There are 3 main steps in the printing process: • Taping • Line up • Print The first part of the process is taping your screen so no ink leaks through. • First you have to tape the outer edges of the screen with the thick masking tape. • Then you tape the smaller pin holes and eventually your registration marks with the thin masking tape.
The next step is very important because if you screw up your design will be crooked not centered on your substrate! To avoid the outcomes listed above you must: • First line up your registration marks to the lines on your palette • Then line up your image relative to the 3 inch down horizontal line • Next you have to line up your substrate relative to where you want it and the lines on the palette
PRINTING PROCESS (CONT.) The Final part of the print process is doing the actual print For the print there aren’t many steps and it is very simple • First get your ink and place it under your bottom registration mark like so
• Next you want to find a squeegee that sticks out about an inch past your image on both sides • Then perform a flood stroke towards yourself with the screen off of the palette • (A flood stroke essentially floods the image with ink)
• Finally you do 2 print strokes in which you drop the screen onto the palette • The first one is right after the flood stroke leaving a majority of the ink behind • The second one you take all the leftover ink and print away from you
CLEAN UP PROCESS The cleanup of process of clean may be one of the less fun of the group, but it is equally important as the others because it frees up screens for others to use. The First thing that you want to do when cleaning up is grab the ink cards and extract all of the ink from the screen and squeegee as you can and put it back into the paint cups. Next wipe down your squeegee and screen using the screen washing spray and the paper towel sheets until they are both spotless of ink.
Then you put your screen into the chemical tank for around three minutes to help remove the emulsion.
Finally use the power washer to fully remove the emulsion and any other leftovers on the screen. (After that degrease with spray and power wash again).
Now place your screen on a drying rack and clean up the counter where you cleaned your screen!
NOW YOU’RE READY TO GO DO IT YOURSELF!