Sharper practices
The Canmaker
June 2006
Reduced lead times, increased productivity, cost savings and environmental benefits. Too good to be true? Not with the latest pre-press developments. Mónica Higuera reports
Canmakers and metal decorators are increasingly aware of the need to invest in digital pre-press technology to achieve not only sharper images but a simplified workflow that enables easier communication with customers, particularly at the design-approval stage.
Demands from customers are also driving a series of improvements in prepress technology whose advantages include reduced lead times, greater flexibility, and shorter print runs without a cost penalty.
Typical of those ahead of the game is Spanish metal decorator Litografía Alavesa (Litalsa) which has been expanding its prepress department over a number of years. Based near Logroño in northern Spain, the company is building on what it considers to be one of its strengths.
“Pre-press is one of the fundamental pillars of the company. If this fails it then doesn’t matter how good the printer might be. Pre-press represents, at least, 50 percent of the end product,” says Litalsa’s managing director Juan Inchausti.
Litalsa recently installed Agfa’s latest generation of thermal platesetters, the Avalon VLF. “It allows us to improve printing quality since a high-defi- nition laser generates the dot on thermal plates straight from the computer,” explains Inchausti.
The company also invested in Agfa’s workflow system, called ApogeeX Light. “But this is only one step forward,” adds Inchausti. “An additional challenge is to achieve the reproduction of the printer at the pre-press stage, by using some digital tool that enables us to foresee the final result. This way we can retouch the jobs more accurately, avoiding machine downtime and correction of plates when printing,” he says.
This has been attained with colour-management software — ColorProof and Dot- Proof from German supplier GMG — for an Epson 7800. ColorProof is used to calibrate digital inkjet proofing engines to make contract colour proofs, while DotProof is said to enable the output of digital halftone contract proofs.
Litalsa is also moving forward on other fronts. “We are now working to place the colour space of our printed jobs within ISO norms being used on the paper sector,” Inchausti explains, referring to the ISO 12647-2:2004, which specifies a number of process parameters and their values to be applied when preparing separations for four-colour offset printing or when producing four-colour prints.
“We are also testing environmentallyfriendly thermal plates by Agfa,” he says. “In order to develop these plates there is no need for chemical baths with high pH, which at the moment is treated as waste. This type of plate can only be filmed with state-of-theart CTP.”
In 2003, Litalsa installed a sixcolour Metalstar2 from Bauer+Kunzi. “We are immersed in Hexachrome printing with our six-colour press to increase our colour space while decreasing consumption of special inks. We use either FM screening or hybrid systems (stochastic-traditional) with a higher number of dots per centimeter,” he says.
In the UK, Impress’s general line canmaking plant at Norwich also uses a Hexachrome- type process but on a pair of twocolour Crabtree Marquess presses, converted to UV curing, and a UV Crabtree 1290 tandem decorator.
This process is being supported by a digital pre-press system following the installation last year of an Xcalibur VLF platesetter by Agfa.
By replacing traditional plate-making technology with a CTP system, an in-house ISO procedure (ISO 9001-2000) was no longer applicable, explains graphics manager Peter Hall.
“I needed to supply our print department with a colour print of the design for checking against the printing plates,” he says. “Agfa advised that the Grand Sherpa was capable of more than just a colour print but could be colour calibrated to match press performance.
“This is when I gave them the challenge to prove this process for metal decoration where we have several constraints such as substrate, over-varnish and the requirement to be able to match the Impress sixcolour print process, bearing in mind the Sherpa is basically a four-colour system,” says Hall.
Impress’s main repro studio, Springfield Solutions Ltd (formerly Fort Dearborn Company in the UK), also purchased a Grand Sherpa device as part of the development.
The three companies jointly developed technology to produce digital paper proofs for printing on metal.
“The first step was to match the Impress six ink colours and develop a method of simulating the colour shade of white base coat we use at Impress. This process has been specifically tailored to the Impress six-colour printing specification. The Springfield group, supplier of the HiColour print process, then added its knowledge of colour measurement,” says Hall.
“It was our initiative that drove this to a commercial conclusion based on the need to meet our customers’demands for reducing speed to market and reduced costs compared with conventional metal proofing. Also we have an added environmental benefit. We are saving metal and coating materials and significant shipping costs as the proof can be produced on site,” he adds.
A“high percentage” of colour consistency was meanwhile achieved, he says, by using colour-washed paper to simulate the appearance of the base metal.
For further Information, please contact:
Agfa, Septestraat 27,
Mortsel 2640, Belgium.
Tel: 32 3 444 9419.
Fax: 32 3 444 9406.
GMG, Moempelgarder Weg 10,
Tübingen 72072, Germany,
Tel: 49 7071 938 740.
Fax: 49 7071 938 7422.
Springfield Solutions,
Units 1-5 Acorn Industrial Estate,
Thomas Street, Hull HU9 1EH, UK.
Tel: 44 1482 226 461.
Fax: 44 1482 225 269.
