GCM 240 Chapter Notes - Chapter 14: Anilox, Flexography, Print Job
29 Nov 2016
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The purpose of proofing an ink is to generate accurate colour matches. Ink should be proofed on the same substrate as the print job. Proof should be compared to the customer-approved standard using a spectrophotometer. Types of proofs are: hand proofers, mechanical bar proofers, and laboratory-scaled flexographic proofing machines. Hand proofers: rubber roll and anilox roller mounted in a frame, ink is applied to the nip between these two rolls, unfortunately, not accurate due to operator influence of speed and pressure. Correlation is confirmed by taking from the press a sample of ink from the ink sump, an unprinted substrate, and a press tear sheet. Proof ink from the ink sump on unprinted substrate and create the standard on the press tear sheet. Measure the proof sample and compare it to the standard (tearsheet) If delta l (difference in lightness) is less than 0. 5, proof-to-press correlation is acceptable.
