by JimRaffel on June 13, 2006
It has been quite a while since I dedicated an entire Golden Nugget to responses I received to a previous Golden Nugget. Two of the responses to ‚Äú#34: On needing color bars to print well“, however, are far too good to not be shared with the rest of my readers.
Comment #1:
While I agree with the end result of your GN, there is 1 VERY, if not MOST important reason for instituting the use of color bars to control and maintain the printing process that was left out.
Even with typical production run lengths becoming shorter and shorter, the fact remains that many jobs carry over from 1 shift to the next. No 2 sets of eyes view color the same way; and I’ve witnessed countless occasions in my career where the “next” pressman makes arbitrary and unnecessary changes to ink viscosity and impression settings only because the color “didn’t look right ” to him. The use of color bars creates an OBJECTIVE set of numerical reference criteria that is agreed upon and maintained by all operators; not having them is an open invitation to SUBJECTIVE and oft times incorrect decision making that adds unwanted variability and cost to the process.
Comment #2:
While I like your map analogy, I think that color bars are more critical than that. I would compare it to an experienced driver making that same route without a gas gauge, speedometer, or mirrors, and with a splintered windshield. Yeah, you could do it, but who would want to?!?
Name withheld
PS-I am a prepress manager 
{
by JimRaffel on June 6, 2006
No, one does not need color bars to print well. You also do not need a map to get from Los Angeles to New York City. I believe we would all agree that with a map, however, the trip from Los Angeles to NYC would be by a more direct route. A more direct route would be faster (more productive) and cost less (use less gas, stay in fewer hotels, etc…).
Yes, I view color bars as the map in the above analogy. I view a pressman with 20 years experience as the truck driver who has made the long haul from LA to NYC several hundred times. Even that truck driver, however, benefits from a map when problems arise (construction, bad weather conditions, etc…).
So, while an excellent pressman can probably produce most jobs quite nicely without ever seeing a color bar; even the seasoned professional benefits from having a color bar when things do not go smoothly. With the color bar we can check density, TVI (Dot Gain), Grey Balance, L*a*b* or inks and spot colors, etc… Armed with that kind of information even a junior pressman can make better decision about how to improve the quality of every job.
More importantly, the color bar is not just for the pressman. The information gathered from the color bar should be fed back to the pre-press department on a regular basis. Pre-press needs to know that the press in continuing to run the same (similar densities, similar TVI, correct L*a*b* of solid ink colors, etc…). With this information pre-press will know that ICC profiles, and plate cut-back curves are still correct. Without it they will just be guessing.
In summary, while complete color quality control systems cost money to put in place the payback is typically much less than one year. Proper use of color measurement instruments and software will result in higher productivity and lower costs. Want to know more? Please feel free to contact me anytime for more information.
{
