Printing Errors: Identifying Responsibility
Printing errors fall into at least three classes:
- those the client is responsible for, such as editorial changes he or she never made,
- errors the printer is responsible for, such as problems with the ink/water balance in offset lithography, and
- unfortunate results that occur due to the limitations of offset printing. (For example, this would include web growth, in which book text paper printed on a web press expands beyond the trim of a cover that has been printed on a sheetfed press).
Blame seldom helps in any of these cases. It is far more useful to view your printer as a partner and work together toward a solution.
A client of mine was recently surprised that he would have to pay for editortrial changes made at the printer's proof stage. There were errors in copy and photo placement, not errors in proofing or printing. My client understood the difference, and he chose certain errors to correct and left the less important errors alone.
The best way to avoid this extra expense is to have an editor carefully proof your work (content, placement on the page, grammar). He or she should make sure nothing is missing, and make multiple passes through the copy, checking for one or two things each time (whether all the folios are present, whether all the margins align as expected, etc.). Time spent in meticulous checking and rechecking at this stage will save you both time and money later. Also, you may want to consider printing a laser copy of your job one final time. It may be easier for you to catch errors in the physical proof that you would miss on the computer screen.
Printer Errors Related to the Ink Water Balance
Offset printing “works” when the balance between ink and water is correct. If the ink and water are not in balance, you will find ink deposits where you don't expect them on a press sheet. You may find streaks on the paper or tails of ink extending from the type letterforms. You can catch these flaws on a press check, or you can request an F&G (folded and gathered signatures of a book that has not yet been bound or trimmed).
Problems of this sort are the responsibility of the printer to correct (or reprint). The good thing about an F&G (as an interim proof) is that, if errors are found, your printer will not need to tear the covers off the printed and bound book, reprint one or more signatures, and then rebind the book. This benefits both of you in terms of turn-around time, product quality, and overall cost.
When dust gets on the printing blanket, it will leave a dark-centered spot on the press sheet surrounded with a white halo (like a little donut). Pressmen watch for this (by pulling proofs throughout the press run) and clean the blankets when they see hickies. Hickies come and go throughout a press run. Unfortunately, they are unavoidable (within reason).
Printing Errors Related to Movement of the Plate or Blanket
“Doubling” occurs when a printing unit picks up a previously printed ink film and redeposits it on a press sheet. In simpler terms, the blanket is printing the image twice. Printers look for this in their periodic proofing during a press run. It can be seen in the elongation of halftone dots.
“Slurring” is another problem involving the elongation of type and images (and can also be seen in the halftone dots). It is not directly related to a “re-deposit” of ink film.
Some of the causes of these two printer's problems are a loose plate, a loose blanket, problems with the packing under the press blanket, and dimensional instability of the paper (which might be caused by problems with the ink/water balance).
Web Growth and Fluting
Both “web growth” and “fluting” reflect physical limitations in the offset printing process. They are nobody's fault, but they can be minimized.
Web growth occurs on heatset web presses. The high heat of the ovens that cure the ink (by flashing off the solvent) also remove much of the water from the press sheet. After the chill rollers have set the ink and the book has been trimmed, the paper absorbs water from the air and grows a little.
If the book covers have been printed via sheetfed offset lithography (rather than heatset web offset lithography), and if they have been affixed to the book blocks without the text blocks' first having been left to adequately acclimate themselves to the surrounding temperature and humidity and reabsorb water, then the text of the books can grow beyond the trimmed covers. Essentially this happens because web growth occurs only on heatset web products (the text) and not on sheetfed products (the covers).
Letting the text signatures sit for a while before binding the book can minimize the problem.
“Fluting” is a waviness in the text stock of the books. Like web growth, this flaw occurs only in heatset web offset lithography. It is considered a “normal” flaw, and yet it can be minimized by choosing thicker, rather than thinner, book papers (thicker than 60# text weight, for instance). Avoiding printing a think ink film on both the front and back of a press sheet will also minimize fluting.
I have also seen the waves in the paper relax a bit over about a week's time after delivery. Stacking the books in piles and waiting seems to help (i.e., the weight of the books on each other, and their becoming acclimated to current temperature and humidity conditions, seem to reduce the fluting).
This is a tough call. If you supply halftones with limited tonal range, or moire patterns (caused by scanning an image that has been offset printed and that already has a halftone dot pattern), the final product will reflect these flaws.
However, if the photos look muddy throughout, with consistently plugged up midtones and shadows, look to the printer for an explanation.
It's also wise at this point to look at the images with a loupe. Over-inking, dot gain, and problems with register can cause muddy halftones or color shifts.
Check the images to see whether the process colors are out of alignment. Look for rosette patterns—created by the four process color screens positioned at slight angles to one another. If these circular patterns in the halftones have black dots in the center, there may be registration problems (they should usually have open centers). Also look at type built with multiple process colors (use a loupe). You may see a row of halftone dots hanging slightly out of alignment.
If the color is off (doesn't match the proof), if the press sheets are out of register, or if the halftones are muddy, look to the printer for an explanation.
In these cases, the product may need to be reprinted or a discount may be in order.
Physical Problems with Books
I have seen books in which the pages are falling out, and I have seen books with film lamination peeling off the covers or with air bubbles under the cover coating (caused by release of gas as the heavily inked covers dry).
Both of these problems are manufacturing defects. You need to ask your printer what happened. These are serious issues.
When you find a problem and trace it back to its source, the goal is to discover a solution, not lay blame. Most of these problems will probably occur at least once in your professional lives.
The first thing you need to do is send the printer samples (and photos) and document the extent of the problem. If the problem only affects a limited number of copies, you may request a price reduction on the total cost. If you don't have enough usable copies, your printer may need to print more.
When I found that all copies of my client's book had air bubbles under the film laminate coating, my printer stepped up to correct the problem. Instead of reprinting the entire job, he removed the bound covers, reprinted and laminated the covers, bound the book, and then trimmed each one by hand to ensure a perfect trim. Granted, this took a while to complete, so I had to devise a printing and delivery schedule with my client that made sure she had enough books for her clients throughout the process. The printer sent my client several batches, which she approved as they arrived. It took a long time, but the client had enough books at each stage to fulfill her book orders. And the printer didn't have to scrap the whole job. Keep a positive attitude, and work together with your printer to resolve the issues.
Compromise is a virtue.
[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]