"Fine Lines of Communication"
[Column #10, 10/95]
As you may have gathered from reading my previous columns, I'm big on dialogue. This month, I'm going to focus on the fine art of nonverbal communication between printers and finishers. You'll be relieved to know that the language I have in mind does not involve rude gestures-nor, for that matter, genuflection.
The communication takes the form of marks made on film during prepress which appear on the press sheet, where they provide an essential means of communication from prepress to press and postpress staff. A code shared by printer and finisher, the marks ensure that everyone in the production process knows what's what. For the many people new to our trade information about the marks will be useful.
Although there is no formal, standardized set of marks, there is general agreement on the main types and their functions. The important thing is that all parties have a common understanding of the code, not that every printer and finisher make exactly the same marks. The goal is better communications, fewer errors and more efficient production.
Center marks, tic marks, register marks-whatever you want to call these things-are very important postpress finishing guides. Unfortunately, with all the preregister devices being used, a lot of printers have abandoned some of the practices that binders and finishers have long relied on. Side guide marks are absent in many cases, making detective work out of determining which side is which. Even if a tag is in the load of paper indicating "side guide," without a visual mark running down the whole load, we still have to make sure that the tag is on the correct side.
Each side of a press sheet is identified by a name-specifically, "gripper edge," "side guide," "trailing edge" and "offguide." Binders and finishers need to be able to identify the side guide and gripper edges before they can perform postpress operations.
After the sides have been identified, the next step is to ensure that the press sheets are in register with each other. If there were side guide or gripper problems in printing, then any critical downstream operation will be adversely affected. It's at this point that "center marks" come into play.
A center mark is a one-point rule that bleeds off three sides of a press sheet-as in the illustration below. The center mark indicates if the press work was in register from sheet to sheet. A lift of paper, jogged to its proper guides, will ideally show the center mark as a straight line running down the lift of paper. If the line's not straight, you have an inconsistent sheet-to-sheet register and a quality decision is going to have to be made.
There can be other printed aids on a press sheet-fold marks, final trim marks, version or volume number notes, collating marks, etc. Collating marks are also known as "plugs"-short lines about 3/32" thick and printed on the spine of each signature in a stairstep fashion, as shown below. These plugs give the binder an immediate visual reference showing the integrity of the collation.
In addition to all the printed marks, every job should, ideally, come with a "rule-up," a press sheet on which rules have been drawn from the marks to show trim, final size, perforations, scoring, folding, etc. A "folded dummy" is another important visual aid. Often the dummy is a blueline that's been folded and marked to look like the finished piece. Or it may be a folded blank sheet that was originally created for planning and estimating purposes. If the printer has been working with the finisher from the outset of a job, the finisher often makes the folding dummy.
Finally, I'd like to add a corollary to Marty's Maxim #1, which you'll of course remember is "Always consult with your finisher in advance."
Here it is, the Corollary to Marty's Maxim #1: "Communicate with your finisher until the finishing's finished." I think you'll find that all these marks, as well as the rule-up and folded dummy, are essential means of communication and will prove their worth with the successful completion of your projects.