3800 marks in the middle of the print

[Kirk Gittings]

Out of the blue, after printing on the same media for a week with no problems (PK-Canson Plantine Fiber Rag 13x19), I get these tank tread marks in the middle of my prints. They start about 1/3 of the way into the print and run through till the end. The "track" runs in the feed direction. The paper is good and flat and fed through the sheet feeder in back.

Thoughts? I am under the gun here.

[Kirk Gittings]

Hmmm....I ran some nozzle checks and alignment and it seems to be ok now.

Have any idea what it was? I've never seen it before.

[Mark D Segal]

What platen gap and media thickness settings are you using?

[Kirk Gittings]

Thanks,

Platen Gap-Auto
Paper Thickness-3

AND the marks are not gone-just fainter. I was so tired last night that I didn't see that they were still slightly there. It became obvious when I was fresh this morning.

I ran across a posting by MM Chan on this he suggested setting PG to wide and increasing drying time. I am running a test with the PG set to wide now.

[Mark D Segal]

If that paper is thicker than Epson Enhanced Matte or Premium Luster (or whatever they call them these days, I recommend that you set the platen gap to "wider" and the paper thickness to at least 4. Run a print and see whether that solves the problem. You can increase both settings further if you see improvement but not disappearance of the issue at those settings.

[Alan Goldhammer]

I echo Mark's reply.  I have done some printing on this paper and the problem is you need to look carefully at the paper specification when using non-Epson papers since the base default settings for the printer are often wrong (I have a 3880) since they are for the corresponding Epson paper which may be thinner and have different ink absorption properties.  I have used 'wide' and '4' when printing on this paper and it seems to work fine (though most of my printing is done on Ilford Gold Fiber Silk and Museo Silver Rag).

[Kirk Gittings]

Thanks guys. So this problem is a caused by the head hitting the paper as it swells from ink absorption?

Setting the Platen gap to Wide seems to have worked. I will watch it very closely (and make more adjustments as necessary) as I have just enough paper to finish printing this show and it hangs next Thursday!

Oddly, I had done 15 perfect prints on this paper with the original paper settings, all from the same box before the problem appeared. But on very close inspection it did show up very very faintly on about half the prints.

[Mark D Segal]

Oddly, I had done 15 perfect prints on this paper with the original paper settings, all from the same box before the problem appeared. But on very close inspection it did show up very very faintly on about half the prints.

Not odd. It's not at all unusual for this problem to be intermittent, so best is to go for the settings that assure a smooth ride.

[Farmer]

The difference between a head strike or not is very, very fine.  Changes in temperature, humdity, media consistency etc can all affect it - hence intermittent.

[Kirk Gittings]

I've thought of those possibilites but the paper was from the same box and weather has been dry and consistent. Must be something I am overlooking, but changing the Platten Gap solved the problem.