Panthala Selvan conducting a workshop
Case-study: achieving colour accuracy with the use of right substrate
This particular project took place at Dhaka in Bangladesh. The client had to print a test chart on a specific substrate (grey-back board) conforming to a particular print buyer standard. This standard was close to ISO 12647-2 standard.
There was scoring for the print result. The requirement was 90% of the standard. We needed to strike CMYK dE (Delta-E) value of less than five.
Then there were areas like board (substrate) dE, overprint, trapping, dot gains, grey balance all within the specified standard.
Customer expected grey-back board whiteness equivalent to white-back board. Since the board dE was completely out of tolerance level, we couldn’t hit the CMYK dE and other parameters. We tried with all available boards from the local market. Due to variation in board colour, we couldn’t hit CMYK dE within tolerance levels. We even tried different ink sets. Finally we found a particular board that was close to our requirement. Half of the board was very good (the score was 90%) and the other half was 80%. Now we had to use three brands of inks to hit CMYK dE on that board.
Finally we scored 90% as average and passed the test. This was stressful for us as well as the owner. Somehow we succeeded at that time.
One month after that when the printer’s client visited the shopfloor for an audit, we had to reprint and get the same score in front of them. But this time around we imported the board from India and the results were above the 90% score and that too within an hour of loading the job.
The basic lesson from this case study is that achieving colour accuracy is easy when you have the right substrate.