How screen printing works?

So how exactly does your logo get on a shirt?  In today’s Friday Feature we explore how, exactly, screen printing works.

Art Prep

When your design is approved our design department spits the artwork up into several black and white files, one for each color in your design.  These files are then sent back to our screen department to be imaged.
Simple spot color jobs are usually quick to separate.  Simulated process jobs, however, take more time.  On the jobs different inks are printed on top of one another to simulate additional colors.  Greater care must be taken in the initial prep of the file to make sure everything will print successfully.

Screen Prep

In the dark room, the art department’s files are applied to screens coated with a light sensitive emulsion.  At Dynamic Designs we use a direct-to-screen printer to apply opaque wax to the back side of the screens.  These imaged screens are then exposed to a bright light source.  While on the exposure table the opaque wax blocks the light from the graphics; while the rest of the exposed emulsion hardens.
After being exposed the screens are taken to a washout area.  The protected portions of the screen are now rinsed away leaving a stencil in the screen’s mesh.

Setting up the Press

Once all the screens for a job have been imaged they are loaded into one of out five automatic presses.  A press operator then registers the screens together, loads the correct colors into the screens and prepares to make a test print.

Printing Your Shirts

After everything is inked up and registered we are finally ready to print some shirts!  Each garment gets loaded onto an arm of the press and takes a trip around, gaining a color at each head.
Dark garments will usually have a white underbase printed and dried (or flashed) before getting colors on top of it.  The reason for this is the general transparency on inks.  Imagine trying to use markers to write on black paper.  It wouldn’t show up well would it?  Now if you put some white down on the paper first, your markers would show up just fine.  The same thing applies to screen printing.
After a trip around the press the garments are taken off and run through a dryer, heating the ink to around 320 degrees.  This cures the ink and prevents it from crumbling off the shirt later.
If the garment has an additional imprint location, like a back print or sleeve print, the shirts are stacked back up and the process begins again!