Since 2006 a System Brunner Instrument Flight inline colour measure-ment and closed-loop control has been in action at Melter Druck in Mühlacker near Pforzheim Germany- in web offset printing. The colour security and reliability this solution has ensured each day led to the company deciding to work with Instrument Flight in sheetfed offset print-ing. This system is an extension of a KBA QualiTronic Color Control sys-tem in a KBA Rapida 106.

The Melter group has about 300 employees on its payroll. The company, founded in 1912, specialises in the complete production of direct mailings plus customisable text and image advertising print products with various finishing options. The realisation of drafts and data predominantly from advertising agencies takes place in web offset, sheetfed offset and digital print, as well as many possibilities for inline and offline finishing, post-press and inserting in envelopes. Once again Melter was awarded with the seal of approval from the German Dialogue Marketing Association for the areas of data processing, lettershop and fulfilment. Melter Druck is proof that money can be made by investing in energy-saving kit, such as heatset printing with a thermal air-purification system from KBA MetalPrint. In addition the company has an photovoltaic system with a collector area of over 1,000m² which is equally environmentally friendly.

Since 2006 colour control with grey balance priority

Both Heidelberg-Harris M-600 presses, installed in 1996 and 2001, were equipped with a Color Control System (CCS) from QuadTech combined with the System Brunner Instrument Flight software at the end of 2006. Since then the printing process on the 16-page presses featuring In-strument Flight have been controlled by grey balance priority. Technical manager Klaus-Dieter Marquart says: “We haven’t received any com-plaints regarding the M-600’s colour printing since then.” System Brun-ner, located in Locarno, Switzerland, launched Instrument Flight in 1991 as an online solution for sheetfed offset presses. After two years of de-veloping with QuadTech, in 2000 Instrument Flight was made available for web offset.

What does “grey balance priority” mean?

Colour balance defines the relationships of the process colours with each other in all tonal areas, whereas grey balance defines the colour balance in the grey-scale area. Instrument Flight ensures a transfer from solid ink density regulation to a more precise “grey balance priority”. “Uniform solid priority” evaluates the four individual 100 per cent tone densities CMYK, but disregards important information regarding tonal values as part of the process standards.

In contrast, “grey balance priority” controls individual solid ink densities by taking into account more than 30 image-crucial parameters which are measured in the colour control strip including tonal values in CYMK and the three-colour grey balance fields in mid tone and full tone. This is more effective as 90 per cent of all colour differences arise through tonal fluctuations in the dots when overprinting transparent inks.

System Brunner’s expertise extends beyond numerous parameters. Its evaluation and ranking are crucial. Even the priorities are rated. At Melter the optimum “grey balance priority” does not mean 100 per cent grey balance control in heatset printing, but 60 per cent grey balance com-pared to 40 per cent single colour dot gain influence. In sheetfed offset, however, “grey balance priority” is rated differently.