Hard-Copy Proofs Vs. Virtual Proofs

First of all, let's discuss the specific options and then their benefits and drawbacks.

A hard-copy proof is a digital version of the bluelines, Cromalins, Matchprints, etc., that printers used to burn from negatives. Now, since almost all printers omit the film production step and burn printing plates directly from the digital data, they need to create digital proofs, which are usually produced with some variant of inkjet printing technology.

For example, my book printing client requested book blues (a digital version of the former bluelines) to check the position of all elements in the text of her, and her husband's, book. She also requested a Level 2 proof for the 8-page photo signature that will be bound between book signatures. For the cover she requested a Spectrum proof.

These proofs actually reflect three distinct levels of increasing accuracy within the options for physical proofing (as opposed to virtual proofing). The book blues show position only. They are fine for the text of the book since it includes no photos.

In contrast, the photo signature will be printed on a matte press sheet. It will therefore require more precise proofing capabilities, and the nature of black-only inkjet printing (Level 2 proofs) will make this appropriate for my client to check the photo insert section. Detail in the highlights and shadows of the images will be more defined and will also be more faithful to the final printed output. (Of course, this assumes the printer has calibrated his press and his proofing device to be in synch, but I am confident that this has been done regularly and with precision.)

For the cover of the book, which will be printed in full color, the highest level of accuracy is required, so my client has requested a Spectrum. The Kodak Spectrum (formerly Creo Spectrum) uses the same digital data to both image the proofs and to burn the printing plates. Additionally, the Spectrum reflects the same halftone dot structure that will be in the final printing plates. Due to the high cost of the Spectrum relative to the other processes, my client's reviewing only the 4-color cover using this technology is prudent. The Level 2 proofs will be adequate for checking the black and white halftones for the 8-page insert. A Spectrum proof would be unnecessary.

To be clear, not all printers have dot-for-dot proofing. In your own print buying work, you might want to pose this question to your printing supplier. The benefit of a halftone dot proofing system (in contrast to many continuous tone inkjet proofing devices) is that you will see any moire patterns (undesirable conflicts between the halftone screening and any repeating patterns within the photographic images—like a plaid tie). If you're only using a continuous tone (or contone) proof, you will not see these artifacts until the job actually prints, and by then it will be too late.

My client's print job management software (InSite) does, however, offer one additional proofing option: virtual proofs. As a rule, if they're included in the price of the job, I'm not averse to such an option. However, I would only encourage a client to use virtual proofs (on-screen proofing accessible through such a printing workflow as InSite) to check the position and completeness of all copy. Since there's always a very slim possibility of an art file's creating a problem visible within the proof, it doesn't hurt to review the proofs on-screen or print out laser copies, as long as higher level color proofs are also included in the workflow.

Here's why: If you were to calibrate your monitor regularly using dependable software that mapped the screen image (created with light) to the printer's actual press image (created with ink), and if you were to work in a room unaffected by ambient light (such as sunlight coming through a window and changing as the day progresses), I'd say that your screen proofing would be accurate and adequate. Since I don't know too many people who would arrange for such controlled conditions (other than commercial printers), I'm hesitant to advise clients to use only screen proofing technology.

Specialty Inks

1. Magnetic inks: If you look at the bottom of your bank checks, you will see printed numbers related to the bank and to your account. These are printed with magnetic inks and can be read by your financial institution using MICR (magnetic ink character recognition) equipment. This magnetic substance also comes in laser toner cartridge form as well as inkjet form, allowing you to print checks that are compliant with bank MICR equipment.

2. Food-grade inks: To avoid any chance of food contamination, the FDA has very tight restrictions on the kinds of inks that can be used in food packaging and what kinds of barriers are needed between food items and any ink (a plastic bag inside a cereal box would be a barrier of this kind; it keeps the cereal it contains separate from the packaging). Food-grade inks must meet safety requirements, but they must also be functional. That is, they must be appropriate for the printing substrate you're using and for the printing process itself (such as flexography for printed bags and cartons).

3. Fade-resistant inks: Let's say you're producing a large-format exterior wall hanging. Over time (a short time, actually), the ultraviolet rays of the sun will fade the ink colors in the poster. To be more precise, the reds and yellows in the 4-color images will degrade more quickly than the blues and greens. Fortunately, if you need light-fastness in your printed product, your printer may be able to mix or buy fade-resistant inks. Keep in mind that these inks still fade, just not as quickly. The kind of light makes a difference as do the ink colors involved. Even the particular season may make a difference.

4. Scented inks: Some vendors even provide overprint coatings containing microencapsulated ingredients that release scents when rubbed. This can be particularly effective if you're designing an ad for a new perfume. The client can just rub or scratch the swatch on the print ad to release the scent of the perfume. This can even be done more than once, presumably breaking open different 6- to 10-micron capsules each time the reader rubs the perfume ad.

5. Scuff-resistant inks: Inks can also be configured to be more durable than usual, resisting scuffing and scratching. In this case a wax is added to the ink mixture to harden its surface. Of course, you could also add an overprint varnish, a UV coating, or a laminate, but if the inks are scuff-resistant, you can bypass these additional finishing operations, saving both money and time. You may want to consider scuff-resistant inks if you're designing cartons or other packaging materials.

[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.]