I’ve mentioned “registration” as part of the printing process in an earlier post. Some of you readers might be wondering: what is registration? To put it simply: it’s the method of aligning different colors on the same page. Because printing multiple colors requires multiple plates, each piece of paper is run through the press once for each color. A few weeks ago, I printed 60 3-color invitations: that’s 180 passes through the press, with 3 ink mixes and 3 setups & wash-ups per color.
Aside from multiplying press time, each additional color also makes set-up more challenging: the plates and paper guides have to be repositioned in order to print in the same spot. This method of aligning the printed areas is registration. With some designs, a loose registration doesn’t really matter – and could add some playfulness – but sometimes tighter registration is required so that colors are exactly aligned. Did you know that even an untrained eye can perceive a 1/100th-inch discrepancy in alignment?
Some printers use registration marks on their plates to make sure everything lays neatly on top of each other. In most of my printing, the crop marks play double duty as registration marks. Since I know the crop marks need to hit the paper in exactly the same spot for each color, it’s an easy way to align the plates without much additional setup.
Here’s a step by step of how I printed this most recent 3 color job:
1. set up and print color #1 // this is done like any other set up…plate on the base, print on the paper. At this point, I’m not too worried about where exactly the form hits on the paper, just as long as all the crop marks hit the page.
2. washup & clean
3. ink up color #2 // without the form on the base, apply ink to the ink disk + rollers until you have even coverage
4. register color #2 // adhere the plate to the base (if using photopolymer) or lock up your form in the chase. Print directly on the tympan to see where it hits on the platen. Use pins (that’s where the term pin registration must come from) and poke small holes on the tympan where the crop marks printed. Poke corresponding holes on your printed paper where those crop marks printed. Align the holes with the pins. Add gauge pins or guides to set your paper in place.
5. print color #2
6. repeat steps 2-5 for all subsequent colors until final prints are complete
7. trim // use your crop marks to trim your final piece(s) to size.
Just remember that between plates, you’ll probably have to adjust your packing and make ready…but that’s a given with set up. Also examine the first few prints in each run to make sure everything is hitting correctly. If not, make slight adjustments to your gauge pins or guides.
It’s true, the more colors, the more frustrating the process…but in the end, it’s all seems worth it! Happy printing everyone!