Return of the mysterious ‘dropout banding’

[Mark Elvidge]

its not just the roland that suffers from this, the jv3 is terrible for it.

the W-PASS profiles make life a little better. and pre-feeding the media before printing has been recommended. the frustration is that usually just as you are getting closer to a solution the problem disappears.

it does seem to appear at times of the year that are humid or warm, and then disappears for a while again. your situation may differ.

Its also difficult to pin it entirely on the printer as if this was the case then it would happen all the time and more often.

when examined with a 100x scope, the dots are all there, they are just misplaced slightly. in fact its harder to see the fault with a magnifier than just the naked eye.

sorry i cant be of more help.

[Paul Hodges]

quote mark optimise:

its not just the roland that suffers from this, the jv3 is terrible for it.

the W-PASS profiles make life a little better. and pre-feeding the media before printing has been recommended. the frustration is that usually just as you are getting closer to a solution the problem disappears.

it does seem to appear at times of the year that are humid or warm, and then disappears for a while again. your situation may differ.

Its also difficult to pin it entirely on the printer as if this was the case then it would happen all the time and more often.

when examined with a 100x scope, the dots are all there, they are just misplaced slightly. in fact its harder to see the fault with a magnifier than just the naked eye.

sorry i cant be of more help.

Mark,

You’re pretty much on the money with those remarks because i have found that to be the case too, Roland also told me they get more complaints about it in the warm/humid weather, and of course, you can’t replicate the fault at will either, it’s unpredictable but i have found that it shows up in certain colours worse than others.
It just seems as though the heads don’t deliver the same consistency of ink throughout the whole flood coated job and you get very feint lines here and there.
So if it’s the case that other printers do it also, is this a common problem that we’re all just overlooking because no one knows the answer?

[Ian Bingham]

does it make a difference if the media is unrolled and not pulling through off the roll?
ive had similar to what was described but found it to be media too heavy to pull through

[Paul Hodges]

quote Ian Bingham:

does it make a difference if the media is unrolled and not pulling through off the roll?
ive had similar to what was described but found it to be media too heavy to pull through

Ian, no it’s nothing to do with the media travel, all our media is rolled off loose enough so there is no issue with the motors pulling it through off the roll, it seems purely an issue with the density or consistency of the colour or amount of ink being put down. Either that or it’s flaws in the media not allowing consistent print colour coverage but I doubt it is because it’s happened to us at one time or another on every media we’ve ever used…from vinyl to banner to canvas, even the odd paper print.

Thanks

[Ian Bingham]

sorry to hear it, would it be possible to post a pic of the banding?
Ian

[Mark Elvidge]

actually i forgot to mention that i got sent some samples from a supplier last week that showed this issue and that was on a hp9000 and running from shiraz.

[Mark Elvidge]

"It just seems as though the heads don’t deliver the same consistency of ink throughout the whole flood coated job and you get very feint lines here and there.
So if it’s the case that other printers do it also, is this a common problem that we’re all just overlooking because no one knows the answer?"

when i have scoped all the samples of this fault from various rips, printers and medias, i have always seen that the dots have fired. however in the areas that show the print fault the dots are misplaced.

almost like static has pulled them of trajectory. in the cases i have seen (probably about 10) from various manufacturers of printer,media and software the dots have been firing.

i don’t think its specific to head type either, eg jv3 and Roland sharing same heads. the hp uses a fixed dot completely different head and the issues shows there as well.

i know its frustrating, Ive been on site trying to fix it!

[Ian Bingham]

would wiping the media with an antistatic cloth make a difference

[Paul Hodges]

quote Ian Bingham:

would wiping the media with an antistatic cloth make a difference

maybe, haven’t tried that. the static theory may be right because i see this much more on banner media than i do on vinyl, or at least it seems to show more on banner media. i would assume banner media is more susceptible to static charge?

[Paul Hodges]

quote Ian Bingham:

sorry to hear it, would it be possible to post a pic of the banding?
Ian

probably not completely accurate to describe this as banding, most people would think of mechanical banding and it’s not defined like that it’s more like fuzzy lines in the scan direction that are maybe 5 or 10% lighter than the colour you’re printing so they show up as feint lines, sometimes you have to look closely to see them but in darker colours they are more obvious.

[Mark Elvidge]

it looks like media bruising however i dont think it is.

[Paul Hodges]

Mark, I thought that at first but I think it happens too often across the board for that to be the case.

So the dots are going down in the patchy areas, just not in the right places…I’m suspecting static charge from the roll media – particularly banner media – maybe causing this mis alignment of the dot pattern.

We may try to earth our printer and the media before it gets to the heads and see if that stops this problem once and for all