This article is broken into four sections:

• The Proofing Process
• Color Basics
• Analog Proofing
• Digital Proofing

The Proofing Process

Color proofing remains the most contentious and poorly understood process in commercial printing. Proofing affects every aspect and every person involved in a print project. Designers can fuss and fret over choosing the "perfect" hues, shades, and contrasts in their creation. Professional preflight and prepress operators may make color fidelity their number one priority. The most expensive and intricate proofing equipment available can be utilized. The press operators may sweat the slightest color variances on the press, fiddling with every control to produce the perfect press run. Yet, even with all that, results that match expectations are anything but guaranteed.

Anyone who has ever sent even the simplest job to a desktop printer has at some point picked up a printed page and wondered how their job could have gone so terribly wrong. Involve more people, add complexity to your project, increase the financial stakes and you almost ensure that final output and initial concept will be laughably dissimilar. The problem, of course, isn't funny if it is your project, your money, and your livelihood depending upon a successful printing.

The answer, of course, is proofing. Proofs are generally generated at various stages in the print process. In most cases, the type of print job, printing budget, time requirements, and of course, available equipment, determines which proofing steps should be used.

Simple spot-color jobs are often proofed with nothing more than an inexpensive desktop inkjet or color laser. A complex document with full-color images being printed on a high-quality press may have proofs generated at nearly every step of the process.

In a typical color job the proof steps would be as follows:

• Layout proof -- typically printed from the layout/creation program to an inexpensive inkjet or even a monochrome laser. Increasingly, Adobe Acrobat PDF files are used in this step. The PDF can be generated and sent in about the time required to print to most desktop printers. The resulting PDF file (moderately to heavily compressed) is easily transmitted by modem and virtually every client has access to the free Acrobat reader.
• Color layout proof -- actually only a slight step beyond the layout proof. Typically, this proof is created with more accurate colors, usually utilizing a printer with some level of color calibration. PDF files are very popular in this step, but because color values vary so dramatically from monitor to monitor and then again to print, they aren't suitable for most "contract" proofs.
• Analog contract proof -- traditional analog contract proofing uses the actual film output and often the print stock to be used. This results in highly accurate proofs, suitable for use by the press operators in final print control. However, with digital presses and CTP (computer-to-plate) technologies becoming increasingly popular, there is no film generated, thus no opportunity to create analog proofs.
• Digital contract proof -- in essence, a digital proof differs little from a color layout proof except in what it attempts to match. The contract proof might be generated by the very same printer used in the earlier proof, but rather than calibrating output to match the designer's monitor or submitted color samples, the digital contract proof must accurately mimic the color/output characteristics of the press.
• Press check -- although most printers cringe at the thought of clients considering a press check as a form of proofing, the reality is that exacting clients expect this service. As the name implies, this "proof" is actually produced on the press. Typically, only relatively minor color adjustments can be made on the press. Content editing and major color changes almost always require new printing plates to be created. If you need to pull a job from the press, your proofing system has failed.

Naturally, depending upon the client, each proofing stage may include multiple cycles of proofing, reviewing, revising, and re-proofing before client acceptance and moving on to the next stage.

In the next section, we discuss color proofing issues and challenges and look at the strengths and weaknesses of the various proofing systems.
Jump to Color Proofing issues