Implementation of FM screening at HT Media
There is a three-fold need for using new age screening method with changes in the gsm used, the quality enhancement and to save ink.
03 Sep 2015 | 2656 Views | By Priya Raju
Anjan Mazumdar, vice president - quality and EHS, HT Media explained the systematic approach to implement FM screen in newspaper production. He further described the various challenges in the implementation of the method and achieve perfection in a systematic way.
Mazumdar explained, “Unlike in the AM type of screening where the dot size varies as per tonal value; in FM screen, the shape of the dots remain the same, whereas the center to center distance and the size of the dots vary.
The criteria for selecting FM screen at HT Media were to ensure smooth dot rendering, easy control of dot gain, ease of ink control and compatibility with the existing workflow among many other criterias.
Mazumdar explained, “The roadmap to the standardisation involved compatibility study of the plates used, proper linearisation and calibration of CTP for even dot reproduction across the plate was studied.” A dot gain of 26% was established along with the conducting of dot gain analysis. The dot reproduction behaviour in shadow, highlight and mid-tone area was mapped along with many other measures.
Machine to machine dot gain calibration was needed, Mazumdar said, “We designed a special patch to monitor progressive dot gain which is critical in the process.”
He further added that “The FM screen needs a suitable environment and a tight process control.” Once implemented, to ensure a standard quality the CTP optics and processor maintenance has to be to be done regularly as per set schedule.
Also, periodic dot gain analysis of machines needs to be done, and if required modification of press curve is required. In addition to this it is essential to develop suitable ink density standards should be maintained and finally a calibrated densitometer should be used.
HT Media has been successful in reducing 60% of paper consumption to 40 and 42 gsm. “Our advertisers and readers are happy with the print reproduction of HT on FM. And by using FM we have saved 5-10% of ink used,” concluded Mazumdar.