Mimaki and Bi Directional Printing

[Jeff G]

Hey All,
I guess first of all a quick little intro, as this is my first post and all, working out of Calgary Alberta in a larger print shop. Working here as a Artist and printer on our Mimaki's. Was hired as just an artist but out Mimaki guy went over the fence, I was the only person with any Mimaki experiance.

Any-hoo....

I have been working with the JV33's for a little bit now, using Onyx as our ripper and I have encountered an interesting problem.

Basically the printer looks like it is printing in a stripe pattern. Every other pass is coming out lighter, then darker, then lighter and so on. The less passes I do ( 4 pass to 8 pass) you can really tell the difference. Higher number of passes seem to hide to issue but it is still there.

The biggest difference is when I change from bi-directional printing to uni-directional, it all but goes away.

Has anyone incountered anything like this? Or any ideas to fix this? So I have reinstalled Onyx, remade profiles, changed setting in the Mimaki, and nothing seems to work. It is happening on both of my Mimakis so it has to be something I am doing with both of them.

If this makes any sense, then I must not be as tired as I feel. I am thinking that it is just a simple issue to fix, I just can not think of what it is, which brings me to you guys!

Thanks in advance....

~Jeff

 

[Case]

[FONT=&quot]If you are getting a light-dark banding, there are few things to try to correct this.[/FONT]

[FONT=&quot]During winter times, low humidity in the air will cause the ink to dry too quickly[/FONT]
[FONT=&quot] a. Lower the heat settings[/FONT]
[FONT=&quot] b. Print faster by changing the print speed in the ripping software.[/FONT]
[FONT=&quot] c. Print unidirectionally instead of bi-directionally or even vice versa in some cases.[/FONT]
[FONT=&quot] d. Lower the number of passes.[/FONT]
[FONT=&quot] e. Increase the humidity in the air.(40-60% humidity ideal)(humidifier)[/FONT]
[FONT=&quot] f. Print at 16 passes (kind of a catch all the cures most problems)[/FONT]

[FONT=&quot]During summer times, high humidity in the air will cause the ink to not dry fast enough.[/FONT]
[FONT=&quot] a. Raise the heat settings[/FONT]
[FONT=&quot] b. Print slower by changing the print speed in the ripping software.[/FONT]
[FONT=&quot] c. Print uni-directionally instead of bi-idirectionally.[/FONT]
[FONT=&quot] d. Increase the number of passes.[/FONT]
[FONT=&quot] e. Decrease the humidity in the air.(de-humidifier)[/FONT]
[FONT=&quot] f. Print at 16 passes (kind of a catch all the cures most problems)[/FONT]





Here are some things to try...

Case

 

[Jeff G]

Thanks, some of the things that I have been trying, and the others I will try out.
Right now I have a main humidifier that controls the shop, and then I have three set up around the Mimaki that I am working with, so far not working that great.
It has been really weird because the problem only popped up over the last few weeks.
My big hope is this is happening because the weather here is really all over the place (in the last week it has been -20 C to +10 C) and everytime I compensate one way, the other pops up.
Thanks, need to ease my fears....

 

[eforer]

Is the entire scan lighter or is this just a media compensation problem?

 

[Graphics2u]

Is the entire scan lighter or is this just a media compensation problem?

I've had a simailar issue with my Falcon II Outdoor. the entire scan is lighter.

Raising the humidity helps but doesn't always cure the problem. I've had the problem one day and the next day it's rainig outside and the thing prints flawlessly! So hope for rain I guess, Man and I really like the sunny days!

 

[RaceWrap]

Your problem is not the humidity or media compensation although those to do correct some other issues that you did not mention here. The problem is the Mimaki cromatic banding as it is called. The reason that you do not get it in uni directional mode is that all passes are built the same. If you make a pass in uni you build the color in order...BMCYLmLc.If you build the color in bi, on the reverse pass the color is built backwards because the heads did not also turn around per say. Other printer have what is called fast four. The head is configured as such LcLmYCMBBMCYLmLC. As you can see no matter what direction you are printing the color is buil the smae way. You can run blacks in Bi and not have a problem.......using 50.50.100....360x360 Hi speed and get quick output, but will need possibly 1-2 sec pass delay for drying. IMHO