Printing & Design Tips: APRIL 2009, #93

Thoughts on Varnish and Other On-Press and Off-Press Coatings

Beyond the aesthetic reasons to add varnish or another coating to your press sheet, these coatings protect against scuffing. When your ink coating is fragile, for one reason or another, it’s prudent to add varnish, UV coating, aqueous coating, liquid laminate, or film laminate.

For example, let’s say the cover of your saddle-stitched booklet has a solid coverage of PMS 286 painting the sheet. First of all, PMS 286 contains a lot of Reflex Blue in its composition. And Reflex Blue doesn’t dry well or quickly. In fact, I’m not sure it ever dries completely. Also, heavy coverage of ink (offset ink at least) is more likely to scratch and come off the press sheet than, say, a minimal coating of the same ink used only for blue type on a white background. More coverage means more likelihood of scuffing.

This would be a good time to add an on-press or off-press coating.

One interesting thing to note at this point is that if your job is running on a digital press—specifically an electrophotographic press, or xerographic press—varnishing the sheet won’t be necessary. The xerographic process fuses the toner to the sheet well enough that it won’t rub off. On some digital presses, in fact, it’s not even possible to successfully add a layer of varnish over the xerographic toner. In addition to being more rub resistant than offset inks, digital toners have their own gloss sheen. Therefore, using these digital presses may save you money on shorter runs.

One last thought about coatings: If you varnish or UV coat a book cover, discuss with your print provider whether your job will be more or less likely to show fingerprints. Dull coatings, such as dull film laminate, and gloss coatings can accentuate fingerprints. This happens more often with darker colors than with lighter colors. Look at printer’s samples, leave fingerprints on the coatings that cover the color you selected, and see whether the product meets your standards.

Another thing to keep in mind is that cover coatings are slick. If you open a carton of printed, coated, saddle-stitched books and stack them on a table, you will find that they slip and slide around. So be prepared. Gloss coatings seem to cause more of a problem than dull or matte coatings. This may be an issue, for example, at a trade show, if you want to stack up booklets to give away.

What is a Hinge Card?

Most printers will add this option for free when you produce a perfect-bound book. It’s called a hinge score. It’s a score—a crease—running parallel to the bind-edge (or spine) of a book, approximately ¾ of an inch from the spine. It adds an elegant look to a finished paper-bound book, and it allows you to bend back the cover without causing unsightly creasing or cracking. And, as I mentioned, it’s usually free, since you’re already binding the book. Ask your printer to show you a sample, and make sure he plans to incorporate this feature into your book cover

Avoid Screens of Red

You may be designing a brochure cover one day, perhaps using a PMS blue, a PMS red, and black ink. To vary the color, you may choose to screen back the red (creating a tint of red). If you do, be careful. A screen of red usually has a pinkish cast, which some may find undesirable. Screens of other colors can also manifest undesirable outcomes, but the human eye is more forgiving with most other colors.

To make matters worse, you may not actually see the pinkish cast from the red screen until your job has been printed. Both your monitor and your ink-jet proofer may not accurately reflect the true color.

Problems may occur because your monitor may not be calibrated. The color may be inaccurate. It takes a fair amount of work and specialized equipment, plus the ability to provide consistent light in your viewing area, to ensure that the color on your screen will be dead-on. In addition, color on a video screen is a mixture of red, green, and blue light, whereas offset printing uses cyan, magenta, yellow, and black inks (or PMS inks) to produce color. Therefore, color on the monitor is only a visual approximation of the color that appears on the final printed piece.

The proof might also be problematic in another way. Although an ink-jet printer will produce accurate process color images with a combination of cyan, magenta, yellow, and black inks, if your printed piece includes PMS colors, these will only be simulated by CMYK “builds.”

Again, your monitor won’t show you the exact color that will appear on the press sheet, and your proof will only show you the exact color to expect if you exclude PMS colors.

What can you do? Besides not screening back red, for example, another option is to ask for a “press proof” using the PMS colors you have actually specified. However, this can be very expensive. It can cost multiple hundreds of dollars to over a thousand dollars or more. A press proof is essentially a complete press run just to produce a single proof. It is usually prohibitive in price, but for an annual report or some other high-profile showcase piece, it can be a prudent choice.


[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.]