Speckly areas of single colour.

[Stick It On]

Hi, I have recently bought a Mimaki JV33 with the aim of printing short runs of stickers and labels. I use ES3 inks and a roll of Ritrama RiJet vinyl which was supplied with the printer, and use an ES3 GPVC profile from Mimaki.

I am quite happy with the print quality however areas of single colour seem to come out very speckly, especially greens. This looks fine for large banners but not so great for small product labels that people will look at closely.

I have tried different heat settings and adjusting the quality settings. Is it possible the vinyl may not be absorbing the ink well? should I try a different vinyl? Did I get the wrong printer for doing small prints?!!

Any Suggestions would be greatly appreciated.

Thanks

Mark

 

[GK]

When you say speckly do you mean white areas where ink didn't absorb or does it look like a contamination to the material. Post some photos you will probably get more responses. If you see white areas where the ink didn't adhere/absorb you may need to profile the printer for that media and change your ink limits because you might be over-saturating the prints.

 

[Stick It On]

White areas where the ink didn't absorb is what I mean, tiny little white spots which are not overly obvious in poor light but stand out in good light and make the colour look grainy. It never happens to the black ink, only colour.

I'll look into changing the ink limits. Thanks.

 

[Stick It On]

I have been able to improve the colours by increasing the density and ink limits (although I think that changes the colour too) in rasterlink. Primary colours usually look fine, cyan always coming last in quality. This is not an issue when doing a large print but when printing a business card size sticker it doesn't look so great.

I have attached a sample print that is enlarged. Is this a standard result for a wide format inkjet printer or should I be able to get smoother colours?

 

[eforer]

If you change your ink limits you will change the appearance of colors. It will pretty much ruin the profile.

As far as the "speckles" go: All process colors are made up of little dots of individual colors supplied by the ink set dispersed proportionally to blend together into the ultimate desired color. The distribution of these dots when run in low quality modes such as 360X360 dpi is coarser and will makes the "speckled" effect more pronounced. Are you trying to use a profile for banner material on adhesive backed vinyl? Are you running the head high or low? The effect you are describing is in essence a byproduct of how inkjet printers work, it just seems excessively pronounced in your case, but I'm guessing its a configuration/profile issue.

Make sure your doing something like 720X720 8pass with variable droplet size and have adequate heat on the media to make it receptive to ink. You need to use a profile that is built around these parameters too, not just change the pass count and res of an existing profile.

Hope this helps

 

[PostNet]

I had the same problem when I got mine. The Mimaki rip software profiles suck and only allowed for large dot printing. I had to purchase the Flexi 8.5 print and cut to be able to utilize the variable dot profiles. Although I was able to make it better prior to flexi, flexi was like night and day with crystal clear prints.

 

[Rooster]

For fine detail go to a higher resolution and increase the number of passes.

Switching to the CMYK light cyan + light magenta ink set will clean up those speckles as well.

Printing at 1440x1440/64 pass will all but eliminate any visible dots, but you'll need the patience of a saint to wait for your jobs to finish.

 

[eforer]

The most I'm ever willing to do is 16 pass, otherwise you'll grow old waiting. Keep in mind you will need profiles specifically done for different pass counts. You can't just take an 8 pass profile and switch it to 16 pass and expect it to work well.

Also, while ink limits that are too high can cause fisheyes, ink limits that are too low will cause a greater speckled effect. Go to a better rip, find some better profiles, or better yet, get some hardware and roll your own.

 

[Red Baron]

I had run into the same problem with the exception that it was on banners. I thoroughly cleaned the machine thinking that this would help and it did to a certain point. I did have to change the number of passes used during the print on certain items. This solved the problem. Doing this all the time will make you run out of patience.

 

[Typestries]

was this machine new or used? if used you may need to increase your head voltages, for which you'll need service menu access. As heads age they need more voltage to push the ink through. upping ink limits accomplishes a similar result, but as prev. noted will upset your profile and output.