Improving press productivity with closed loop color control

With shorter print runs, presses are printing many more jobs per day. In this scenario, it becomes particularly important to reduce make-ready time. One way to get there is is with an ink-key presetting system. A typical after-market system consists of software for calculating ink coverage from pre-press data and a hardware box that enables communication with the press console. Ink coverage can be calculated from CIP3/4 or from other RIP formats. Ink presets are optimized by the software based on press characteristics calculated from actual data. The use of ink-key presetting gets the press on color much faster, reducing waste and improving productivity.

With longer print runs, closed-loop color control that keeps the press on color becomes very important. Here, a press sheet scanning spectrophotometer is used to measure the color bars. A 40” sheet can be measured in under 10 seconds. Ink fountain adjustments are calculated by the software and sent to the press console. The console adjusts ink keys so that required density values are maintained for the entire press run. This enables match to reference sheet. The system also enables better adherence to GRACoL G7 and other printing standards. Clients get the highest level of color consistency.


Example of color density variation before and after ink-key adjustment with closed loop

There is a significant cost disadvantage for presses missing ink-key presetting and closed loop controls. Many newer presses include such systems. PressLINK is one of the systems available for retro-fitting to old and new presses from almost all manufacturers. It gives printers a simple way to modernize an older press. Another interesting thing about an after-market system like PressLINK is that a single interface box can support more than one press even if they are from different manufacturers!

Shown below are typical results from using the system on a press.

Productivity gains can save about $150,000 per press per year. Paper savings can be another $25,000 per year. Color control is much improved with 50% reduction in total color variation.

Here is a calculator to estimate savings for your press conditions.