Inkjet image artefacts - seems to be misregister

[LoneGoose]

Hi,

Does any inkjet guru out there have any comments on image artefacts / problems like in attached picture? Is there a name for this beyond "misregistration"? I could only imagine it's the media warping but we've tried upping the vacuum and reducing temperature, to no avail - it's happens randomly maybe every metre or so, only noticeable on black text so far.

We're using Avery MPI3000 on an Epson SureColor S30160 (called 30670 in USA, I think) + Caldera. Screen shot of media settings attached.

Edit: The 'misregister' is showing in the words on the right-hand side. Left-hand side looks fine.

Thanks!

Nicolas

 

[Schnitzel]

What is the printing direction (paper movement) in the attached image - up-down?

It seems to me as though there is a problem with the data flow to the print head at this area, or maybe with the encoder that's controlling the head. I don't believe this is due to paper distortion - that would probably look different.

Can you try to change the color of the text and lines, from black to cyan only, and see if the problem reappears? This may indicate the problem is global and not specific to the black separation.
Also, could you please upload a very high resolution scan of a portion of the problematic area (say, 2400dpi scan)?

 

[LoneGoose]

Awesome idea, thanks, Schnitzel! I'll try with separate C/M/Y versions and will upload here.

 

[LoneGoose]

Sorry for late reply here... Okay, the image "spread" seems to happen randomly in a confined area (like a vertical tear-drop shape) and happens to all colours simultaneously. (Image 001 attached.)

In both images, the feed direction is 'up' (the image came out upside down, printed from top to bottom). The head-movement direction is horizontal / left-to-right.

Image 002 attached is a high-res scan of a good one on the left and a bad one on the right.

 

[Schnitzel]

That's really strange. If I see correctly, the black version is composed of CMYK. All the colors split but stay in registration, which probably means it's a global problem and not related to the black ink or the data that it receives. Maybe the print-head encoder is the problem.
Some things to try further:
- Does it happen with all substrate types or just this one?
- Can you print the same job using a printer driver instead of the Caldera RIP (to check whether the RIP is the culprit)?

 

[Correct Color]

Well, it just about can't be the RIP causing that. My guess would be warped/wrinkled media.

I'll assume you're printing bi-directional. You might try turning to uni and see if that helps.

it's happens randomly maybe every metre or so, only noticeable on black text so far.

My guess is if you look, you'll find it in other areas as well. It's just that it can't hide in the thin text. Most likely what you'll find if you look in areas of solid color, or in images, are areas that appear to be grainier than the areas around them.


Mike Adams
Correct Color