How I Screenprint Yardage November 09 2015, 2 Comments

A friend of mine recently asked me how I screenprint yardage, so I set up my camera on a tripod in my studio to document my first time printing  'Pasto'.
The technique I use for screenprinting yardage is not only the old-school method, it's the ultra-low-tech, do-it-in-your-basement variety.  My grandmother's screenprinting workshop used the same method, but her equipment was much bigger and better.  Behold:
Silvia in her workshop
Most of the screenprinted fabric you see in modern clothing is printed using a completely different method, in which silkscreens are cylinders and the printing table is a conveyer belt.  I have had fabric printed this way in a large factory in Lima.  While the process lacks the charm of manual yardage screenprinting, it's easier to print wider fabrics and it's a whole lot faster.  Here are the cylindrical screens used to print my fabric the modern way:
 Modern cylindrical silkscreens
So if modern factory screenprinting is the most efficient, why don't I stick with that?  Well, I absolutely plan to when I have a few hundred yards of fabric to print all in one go.  But because this expensive machinery is run by engineers, factories require minimums to print yardage - usually several hundred yards per print, per color.  While I work up to those quantities, I'll stick the more rustic (albeit more labor-intensive) process.  
I built my screenprinting table (with more than a little help from my dear dad) by covering a table-top with wool batting and canvas, pulled taught and secured around the edges of the table. My t-square keeps the screen lined up straight across the width of the table.  I made it with a couple of pine 1x4s.
There's a bit of set-up each time I screenprint fabric, especially when it's a new screen.
Step 1: Spread the fabric across the table, iron it to create a flat printing surface, and pin the edges down to keep it in place.  Cover pins with masking tape to keep them from damaging the screen.
Pinning fabric.
Step 2: Measure the repeat length - the length of the print.  The ideal is for the prints to fit together like puzzle pieces, so it's important to measure exactly.  The length of this print is 14 7/8" and trust me, one eighth of an inch is the difference between success and failure.
Measuring repeat
Step 3: Mark the repeat measurements on masking tape down the length of the table.  These are the registration marks that I'll line up my screen with to fit together the "pieces of the puzzle", if you will. 
Marking repeats.
Step 4: Line up the t-square with the first repeat mark on the table, and then create a mark on the t-square itself to line up the bottom corner of the screen.  And with that, I'm ready to print.
Lining up screen
Step 5:  Pour a generous dollop of ink along the entire edge of the design.  Where you see yellow on the screen is where the ink will pass through the screen.  The dark green is photo emulsion which prevents ink from passing through to the fabric.  Place a squeegee in the dollop of ink and push it away with light pressure to coat the design entirely.  This is called "flooding" the screen.
 
Step 6:  Bring the squeegee to the far side of the screen, push down, and pull the squeegee across the screen with firm pressure.  The number of strokes across the screen depends on the screen density, squeegee hardness, ink, and fabric, so getting the print to come out just right often takes a bit of practice.
Printing
Step 7: Repeat at every other registration mark, leaving spaces between prints.  Why print at every other registration mark?  The screen is bigger than the print, and if I were to print the repeats continuously all at once, the screen would pick up wet ink from the surrounding prints and smudge the fabric.  So for now I just print at every other registration mark and wait for those prints to dry.  In the meantime, I'll collect excess ink from the screen to use again and wash my screen and squeegee.
First repeats
Step 8: It takes about half an hour for the first set of prints to dry, along with the screen and squeegee.  When they're ready, line up the t-square and screen at the remaining registration marks and fill in the gaps.
Second repeats
Second repeats printed.
Step 9: Let the ink dry, then set it with an iron.
All the repeats fit together to make a continuous print.  Check out how one repeat completes the next in the two images below.

Pasto repeat 1

 Second repeat detail.