If you’re creating files to send to a commercial printer, you’d better know how to do it right. I could do a Print Tip about file prep every week for six months and not cover all the bases. Suffice it to say (I love using that phrase) that creating good, clean printable files that translate into the colors you EXPECT to see, is neither simple nor a one-step process.

This column was submitted by Ken Hablow, principal of KH Design (http://www.khgraphics.com). With more than 10 years‚ design experience, Ken is a pro yet the learning/finessing continues daily Here’s what Ken had to say about computer monitors and color matching:

“I recently had an exasperating experience with color. I had a photographic image I needed to screen to 10% as a full background and have color separation negatives made for magazine display advertising. The separations are CMYK. Of course, my monitor is RGB, and so was the original photo.

I did all the right things - almost. The photo was purchased as a royalty-free image. Knowing I had to ultimately output this as CMYK, I first converted the image to CMYK in my paint program, manipulated the image to the 10% I needed for the background, and imported the CMYK version into my layout program. It looked great on screen, and the client was happy with the color.

But the computers at the service bureau were not.

The image was a concrete building against a deep blue sky. When screened down to 10%, the building went almost white, which is what we wanted, and the sky to baby blue on my RGB monitor. The CMYK imagesetters and composite printers all output the baby blue as a bland green. I tried PDF files with different settings and also direct PRN files for both the separations and the color matching composites. They all output as green.

My service bureau really keeps the word “service” in their name. For those of you in the Boston area, this is MicroPrint. Their best tech person took the image apart and discovered there was about a 5% difference in the amount of cyan, magenta, and yellow in the sky. At full saturation this would not be a problem, but at 10% this meant there was half as much yellow as cyan; and we all know blue and yellow make green.

It took a lot of work at the service bureau to eliminate all traces of yellow and magenta before the image printed properly, but the final match print was exactly what my client had seen on my monitor.

Another problem was that my service bureau uses a different color matching profile than I do for my equipment, which can alter the color hue and saturation of an image. So, in the future, when I am screening photographic images, I will have a match print made BEFORE I start assembling the page.

This was an expensive lesson as we output three full sets of negatives for the three different magazines before we got it right, several color matching prints and two versions of the ad as a large trade show display. So, the moral of this experience is to work closely with your service bureau, run a match print, and be sure you have the color right before you go to press. What you see on your monitor will probably not match the finished product.”

Designers beware. Thanks for the real-life tutorial, Ken!