Colour management for the pharmaceutical industry
The development and adoption of pharmaceutical specific quality standards by the printing industry has played a vital role in the prevention of packaging and information contamination, but there is little in the standards to facilitate the control or continuous improvement of colour management; an ever increasingly important part of marketing, corporate identity, clinical trials and Point of Sale (PoS) product manufacture.
While certification bodies are hard at work ensuring compliance to contamination and business management standards, it is left to the customer to drive improvements in colour management through ever-tighter specifications.
So what can a customer expect from a printer with respect to colour – are those expectations realistic and is the technology available to meet those expectations?
The challenge of the industry is to ensure that the output from one printer is the same as the output from another, despite the fact that artwork may have originated from different sources and be in different formats, the files may have been processed on different software using different colour profiles, the proofs may have been output on different printers or viewed on different monitors, and finally, the product may be printed on different presses with different settings. In addition, the number of printing press variables that need to be controlled during a print run is vast and largely un-automated.
Printers are expected to compensate on the fly for variability in raw materials; variability in the supply of those materials from different sources; machine variability and variability caused by the physical manufacturing environment. Little sympathy is offered to the printer that delays a job in order to acclimatise the Just-in-Time paper delivery!
Although technology can be utilised to read colour, the variety of systems available make industry standardisation of colour manag-ement very difficult. It has long been held that no two printers can produce the same results. However, the advent of an ISO standard for colour management in lithographic printing (ISO 12647-2) along with new spectrophotometry technology may go some way to alleviate this problem in four-colour printing.
Instead of focusing on ink density, the focus of colour control through ISO 12647-2 is on CIElab colour targeting through spectro-photometry, eliminating the differences in colour output caused by ink variability. Adoption of the standard by printers offers huge benefits for the pharmaceutical industry in the form of standardised, high quality output no matter which print supplier is selected. For the printer it offers quicker manuf-acturing times; reduced waste; a pre-qualification to supply some organisations; high quality print; motivation of staff through skills investment; fewer production problems; new market exploitation and ultimately, reduced costs.
The costs associated with ISO 12647-2 adoption are relatively small, by comparison to the adoption of other standards that may potentially offer less of a quality and marketing opportunity. However, an investment in technology is necessary in order to facilitate measurements across each process.
Colour contract proofing
At Fisherprint, we chose the Epson Stylus Pro 9900 for colour contract proofing. The addition of orange and green ink units provide a much wider colour range giving vivid and stunning results, and the addition of an onboard X-Rite spectro-photometer enables automated proof checks to ISO 12647-7 using tick, cross and percentage indicators as they are produced.
The Epson 9900 is coupled with Bodoni Systems’ pressSIGN software, which enables exporting of data to adjust the plate curve to achieve the correct dot gain with compensations for ink wetness and substrate colour, among its many features. To compliment the new proofing system we have invested in an AGFA Avalon N8 B1 Thermal Platesetter, which provides exceptional registration accuracy, reliability and high quality – with the environmental benefits of a chemical free process.
With printing press technology improving all the time, the capability of press running speeds is ever increasing, as is the need of the printer to utilise the maximum speed available. With the speed of press sampling much slower, colour control must be focused on set-up rather than run sampling – and for control – on CIELab rather than ink density. The need to verify colour through the run statistically is still an important aspect of pharmaceutical manufacture, and this need is met by us using a Heidelberg Image Control system, which produces CIElab SPC charts of colour control from scanned sample sheets selected through the run at customer agreed frequencies. This removes the subjectivity caused by issues such as illuminant metameric failure; where the colour of a product looks different when viewed under customer lighting as opposed to the standard controlled lighting at the printers.
The existence of variability in our physiology makes the true reproduction of printed colour impossible. The eye and the brain may adjust to take account of minor colour fluctuations – some people have colour receptors that can adapt to wider ranges of brightness, and the response of the eye to wavelengths of the visible spectrum is not linear.
So as printers, we must aspire to eliminate variability wherever it is evident through investment in new technology, the adoption of best working practices, traceable calibration, good scheduled maint-enance and the use of staff who can bring a great deal of experience – yet be flexible enough to embrace the changes required.
Michael Grunow is the quality manager at Fisherprint Limited.
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