TIFFEN Colour Separation Guide

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1. The TIFFEN Gray Scale & Colour Control Patches is a quality control device consisting of two components each 8” long.

The TIFFEN Gray Scale is a quality‐control device of stepped, neutral values to help the user to:

• Compare the tone values of reflection originals with the tone values of their reproduced image.
• Compare exposure and printing processes so that changing conditions can be identified, measured, and controlled.
• Balance negatives and positives in traditional color reproduction.
• Determine values for ploting tone‐reproduction curves.
• The gray scale is composed of 20 density steps; each step has a density increment aim of 0.10 and relative density values from a nominal “white” of approximately 0.05 to a 1.95 density black. Density increments are tightly controlled and will vary only slightly from the nominal density value. Neutrality and uniformity are also tightly controlled. The background approximates an 18% neutral gray to neutralize flare and adjacency effects.

The TIFFEN Color Control Patches help the user compare the color of the subject with known printing colors. They also help the graphic arts camera or scanner operators identify color separation negatives and positives for color reproduction processes.

To provide a repeatable reference, these patches are printed using accredited SWOP™ (Specification Web Offset Publications) inks on Kimdura stock (not a SWOP specification). Solid ink densities are within SWOP high‐low targets. Solid colors include the single colors and two‐color overprints of the SWOP chromatic colors, plus a single‐color black. Also included is a three‐color combination of equal values of cyan, magenta, and yellow to differentiate a three‐color black from the single‐color black. The lighter colors represent a press result equaling nominal quartertones with an aim of 25%. As with the gray scale, the background approximates an 18% neutral gray to neutralize flare and adjacency effects.

To use the color patches for color‐separation work:

1. Place the color patches and gray scale next to your reflection copy, making sure you include them in your film size for reproduction. Make your exposures with recommended red, green and blue separation filters.
2. Compare the color patches of each of the three color‐printing negatives (or positives).
3. Film negatives will appear light or clear where ink is to be printed, and dark where no ink is to be printed. Film positives will be just the opposite.

These patches are uncoated and are, therefore, subject to scuffing and abrasion. If you use them often, then we suggest replacing them on a regular basis, approximately once a month.