Thread: Colour sequence on a two-colour press

I recently upgraded from a single colour to a two colour press, both Adast machines. The engineer who installed the machine ran KMYC as the colour sequence. When I ran some old plates that reproduced perfectly on my single colour machine in CMYK sequence, I noticed that Black bold text was overprinted with Cyan and Magenta causing that portion of black to appear faded and showed the outlined of the image that should have been behind.

I solved the problem by adding 1% each of Magenta, Cyan and Yellow during the composing process to get a knock out. Is there any other colour sequence I can use to get the best results and retain black as the last colour...or am I just being biased??

Try running your colour sequence as cyan & magenta on the 1st pass and yellow and black on the 2nd pass. Running the black last will ensure that your bold text and picture shadow areas will benefit from that sequence.

Won't that lead to ink spread in wet-on-wet printing, putting two heavy colours together?

Depends on the image i guess.

If it's a 2 blanket press it should be fine no matter what the color rotation is. When I ran 4 color work 2 colors at a time I ran the Y and the M first. Then C and K last. There was also less color contamination and tracking. And easy wash up from Y&M to C&K. Depending on the fit and trapping of the job sometimes I run the 2 tightest register colors together. Everyone has their tricks and ways they like best. It depends on the spec's of the job.

Thanks, I ran a MY and CK sequence yesterday and it came out just fine. Much more life to the output than KCMY

Color sequence can vary from each job. Most of the time we run M,Y and C,K on a two color. Running darker color first also works well C,M and Y,K. We always run Black last on a two color, mainly so you don't run into Y,M,C over printing K.

Thanks guys. I am back to the tried and trusted CMYK sequence. Have to beware of set up though.

I run YM+CK and have no problems with this sequence. Even though with some jobs that have critical color matches one must run to the specific job.

When i was printing in two color presses we either started with black and yellow or cyan and yellow. Printing yellow first and then black in the same run never worked except in roland ultras in other presses it didnt work. If there was dark skyes we made sure to print magenta before cyan in the second run. When u print in that order, if u didnt have enough yellow u could mix some yellow in the magenta to save the job ( that was before densitometers weren´t used so much ).