OneVision standardises print profile for simultaneous newspaper publications from multiple locations
OneVision Software AG has developed one standard profile for printers of all kinds, including newspaper publishers, having multiple print centres with variables such as different web offset/sheet feed/flexo/gravure presses, plate exposing devices, substrate and ink procurement from different manufacturers. Nilay Patel, Technical Director, OneVision Software AG, gives an insight to this advancement.
Print profile standardisation of OneVision for simultaneous publication of print products from multiple locations has added benefits to compensate L, a, b value of different newsprint shades and ink. It also compensates different printing presses and CtP dot gain. It is designed for single test run to follow newsprint ISO standard/or customised standard and regular timely interval audit without any test run after setup. This standardisation can place one strip of 7 to 10 dot wedge in each ink on edit/ weather page and handle standardisation audit. In this, negligible variation in print appearance/ad and editorial pages are evaluated by qualitative and quantitative method.
Suitably for multi-edition newspapers
This standardisation is most suited for newspaper publishers having print facilities countrywide in multiple locations for instant print and delivery to enhance/retain readership. While doing so each location may use different raw materials/inputs in terms of newsprint, ink, plate and fount. This is essentially done to remain competitive in terms of pricing and to minimise supply chain overheads.
Here is an example—location A is using a particular brand of ink based on the vicinity toward press location that will have optimised transportation cost; similarly, location B may use local newsprint. Geographical distance plays vital role in cost optimisation, thus, brings in variants in raw materials/inputs especially in terms of newsprint and ink. These variants play a major role in picture reproduction hence the need for standardisation of profile to have near identical reproduction in all the print centres of a particular publishing house.
“Newspaper houses use AM screening, 1016 SPI plate exposure, 100 LPI file resolution with ISONewspaperV4 profile. Here we are following ISONewspaperV4 profile dot gain as a standard but one can follow other standard too. All locations need to setup one press test run: may be with multiple press units with condition of blanket life and roller settings (ink roller, plate to blanket settings). For better accuracy, include those press units in test run, where solid ink density is within established tolerance,” explains Nilay.
Step 1: Linearise CtP to compensate for plate dot gain
Location A is having 2 violet CtP. First workflow is to expose tone reproduction dot wedge on CtP, use average tone reproduction of both devices and linearise it.
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Enter CtP tone wedge measurement and linearize CtP. Each postscript/nominal dot should expose with similar dot value on CtP. Plate linearization is essential step to start the process from known condition
Step 2: Print dot gain wedge on press by exposing plate on linearised CtP
Test page covers dot from 0 to 100 percent in CMYKRGB ink-zone. You can also place CMY grey level at bottom. Ideally it is better to place dot gain wedge in horizontal and vertical manner at multiple location on test page. Average of all measurement will provide accurate result to evaluate dot gain (as shown in Dot Gain Wedge figure).
Step 3: To create transfer curve table to match standard dot gain
Measure each dot in CMYK and enter value in excel table. Table provides Murray Davis measurement by densitometer of dot and required ISO standard dot. That will help to compensate dot gain on print to match standard dot gain.
“Let’s take an example. Yellow at 50 percent linearised plate dot is printed 84, while standard dot is 76. Now to match 76 percent standard dot, we need to find exactly at which plate dot Yellow is printed 76. At 40 percent Yellow is printed exactly 76 percent. Same way we need to observe each printed tab and prepare table,” describes Nilay.
Printed test form measurement of each ink is set to match standard dot gain and create Transfer Curve table. The figure CMYK Transfer Curve as Compare to ISO Dot Area is showing graph of ISO Dot Gain, ISO total dot and CMYK transfer curves.
OneVision Raster HD (RIP) provides access to compensate press dot gain. In this, Nilay says, “By using one test run, newspaper houses can set different locations exactly follow one standard dot gain: ISONewspaperV4 dot gain is used here.”
Same steps need to apply at each print location. After that uniform setup is achieved and streamline all printing locations which follow standard dot. News publisher is having standard dot gain at all locations. With regular and timely audit, using small wedge in live print run, news publishers can confirm that all print locations are following standard dot gain. This is fingerprinting of multiple locations with one standard dot gain curve and application of single profile, which provides uniform appearance of print at all locations in both qualitative and quantitative method.