In the case of Harper Corporation of America, the proof is in the ink. Harper has developed technology to ensure that the ink is ready to go to press. According to Tony Donato, Product Development Engineer at Harper, several pieces of equipment are required to proof ink. A hand proofer or ink proofer device (a piece of motorized equipment), along with a correlated volume and line screen proofer roller to the press’s anilox deck, are necessary for this process.
In order to be approved as press-ready, there will also need to be an approved color sample to check Delta E, as well as a wet sample of the ink for testing. The tests will be performed on a substrate that is identical to the finished label job.
“You need to have an understanding of what is required of the ink that is needed for a particular press’s operational parameters,” explains Donato.
Harper currently offers the QD Proofing System, which is fully portable and utility free, so–preventing it from being locked in the ink room. The QD also features constant press loading, quick change anilox rollers, snap-in blade holder, a magnetically-loaded doctor blade, interchangeable anilox and rubber rolls, and more (motorized flatbed tables are available with speeds to 150 fpm.)
In order to use the QD Proofing System, an operator will simply clip the substrate to the QD table. The roller bearing guided carriage is then positioned at the start position. Users will then tilt load the proofing handle assembly in the quick alignment clamps, and easily add the specified ink between the anilox and doctor blade to draw down consistent proofs without variations in operator loading pressure.
“The QD family of ink proofers provides handles that do not have any spring adjustable loading, and the tables constant fixed proofer to substrate loading,” says Donato. “These proofing devices substantially save thousands of dollars.”
Meanwhile, the QD Proofer assembly is a "bladed" hand proofer that utilizes laser engraved anilox rolls. With a consistent loading pressure from the table, the product gives ink room managers the assurance that each operator will get repeatable color results with each drawdown. An ultra-lightweight assembly, solvent resistant transfer roll, and easier clean-up functions highlight this unit.
The ink proofing process has improved significantly over time. “There has been an effort to reduce the variables–especially the human variables– in the ink proofing process,” explains Donato. “For years, ink proofers used to have an adjustable anilox to transfer rubber roller pressure to change density. This made it operator sensitive. Newer proofers have removed the adjustability.”
While there has been an ongoing debate about the necessity of proofing, Donato believes there are multiple benefits to this strategy. “Ink proofing that is correlated to the press speeds up the make-ready and initial job acceptance, which ultimately saves time, money and substrates,” he says.