True Colors

• Densitometers measure the volume of ink being laid down on a substrate. As useful as they are for prepress process control, densitometers cannot guarantee accuracy in terms of shades of color.

Farther downstream, useful quality-control measures include monitoring press runs with inline camera-based systems and employing multi-channel densitometric systems to read the widest range of colors to and provide the press operator with continuous, real-time feedback, reports X-Rite’s Garvis. It is also a good idea to monitor incoming raw materials (e.g. inks) for consistency and accuracy prior to using them on press, she says. Adds Heidelberg’s Koehler, “It is important to place quality control elements on the press form somewhere that will allow process monitoring. In packaging, many times these are placed on the individual products on flaps or folds so that they can be monitored.”