PRINTING MULTIPLE COLORS at a time on a press designed to print only one color at a time can be tricky, but the results are often quite fun and visually exciting. What follows are photos and descriptions of a few projects we've tackled at Lead Graffiti to experiment with the letterpress version of rainbow printing.
By trying something a little different each time, we've been able to substantially increase the number of colors we can print simultaneously, as well as maintain clarity of individual colors over longer print runs.
Essential to all of these rainbow runs is removing the yoke from the vibrating roller of our Vandercook Universal III.
Another important tweak is allowing about 1/8" or so of manually pushing that same roller side-to-side in order to keep the stripes of the multiple inks smooth, given the various amounts of printing surface engaged by each color. How often you actually manipulate the vibrating roller is a personal call based on the actual image and results you are seeking.
The form rollers are engaged with the inking drum only just long enough to refresh the ink between prints in order to further reduce the amount of blending during the entire run.
APHA 2016 Calendar / July
SO THIS IS RAY'S IDEA for the month of July in the 2016 calendar for the Chesapeake Chapter of the American Printing History Association: 31 days in 31 colors, all in one run. The photo at the top of this blog post shows the 31 colors and the type form which was cast as slugs on our Intertype linecaster. The size of the trimmed calendar page is 7" x 11".
Seems simple enough. A major time-consuming part was mixing up 31 distinctly different colors of ink. Since the lines of type were so close together, the corresponding stripes of ink had to be placed tightly side by side and with only the tiniest amount of ink applied to the rollers.
APHA 2018 Calendar / August
WANTING TO GIVE A DIFFERENT TWIST to rainbow printing for 2018, Ray decided to do a 2-run calendar page using about 6 - 8 colors each. The twist here was to print on a larger sheet of paper (about 14" x 18") and rotate the paper for each run.
The gripper edge was recut so that the exact same polymer plate could be printed the first time (as I remember it) rotated 30° and the second time rotated 60° in the other direction. It is a bit easier to follow the color change in the date numbers. The trimmed size of this calendar page is 7" x 11".
Using fewer bands of color allowed for each band to be wider. An issue we had to combat was individual bands of ink occasionally showed up as ragged zigzag edges on the calendar's date boxes. This was most likely due to applying a bit too much ink on those bands, and since the movement of the vibrating roller was severely restricted, excess ink tended to pile up in multiple tiny raised parallel ridges. Manually pushing the roller a tiny fraction from side to side between every other print (versus every 5 prints) helped smooth the ridges until the ink leveled out.
