Enabling true colours

Digital Distributors developed a seven step methodology to achieve predictable, reliable printing.

1. Creating acceptable date
2. Soft proofing and display
3. Data separation, press matching and ink saving
4. Proofing to ISO 12647-7 standards
5. Plate making and checking, process control
6. Print productions to ISO Standards
7. Illumination

Case study: Paarl Print

The challenge at Paarl Print, an existing customer with FOGRA EFI proof certification, was meeting ISO 12647-2 standards on the printing presses despite issues such as excessive total ink and poor data separation. The combination of Alwan CMYK Optimizer and Bodoni Press Sign was recommended, resulting in optimal tone value through changing the curves of the press.

Alwan CMYK Optimizer software in the Pre-press corrects separations upon receipt from clients. When a pdf is queued, the job is confirmed for ISO Sheetfed or ISO Web and the ISO standard is selected according to the paper (either matt or gloss). Alwan CMYK Optimizer analyses the pdfs, detects the output intent and automatically changes the properties of the pdf to match the ISO standard specified.

Ink savings can also be achieved, with the software converting colour separations in a pdf to compensate with black ink for the more expensive yellows, magentas and cyans. An ink saving of 15% to 20% are typical.

Paarl Print’s Pre-press Manager, Martin Koen, comments: “We’re already in a good position to get a good print result because the separations on our plates have been corrected and are in line with the particular printing process, the paper being used and any excess ink (TAC) is reduced to the nominal value.”

The next step was to create press curves, using Bodoni Press Sign, for all Paarl Print’s web and sheetfed presses, one using matt and one using gloss paper. Plates can then be imaged according to the particular press on which a job will be printed, ensuring the plates specify the correct ink loading for each particular press.

Press curves are created by making a linear plate (without press curves assigned) with Bodoni wedges (press strips). The plate is the placed onto the press and run so that the CMYK primary colours are within 5dE of the standard values. A Spectrophotometre is used to scan the printed sheets and information is gathered and compared to the ISO Sheetfed standard. The Bodoni Press Sign software compares the wedges, which specifies the dot gain, with the ISO Sheetfed standards for that particular paper type, calculating the compensation required before providing the correct settings for each particular press on a gloss and matt paper.

With reliable press curves, reliable plates are created. Test sheets are still printed and scanned, while ink duct settings can be automatically adjusted to the specs of that press to ensure the test sheet matches the Epsom. With Bodoni Press Sign created CTP curves, printers can print to a specified end tone value with the assurance that the tone value increase and greybalance is correct. Colour consistency is achieved over the entire print run, resulting in Paarl Print – in this case - offering clients printing in accordance with the ISO 12647-2 standards.