White horizontal lines when using 17 x 25 Harman Gloss Baryta with Epson 3880

[Diamond Star Halo]

I'm consistently getting white (sometimes black) horizontal markings on various parts of my prints using 17x25 Harman Gloss Baryta on my Epson 3880.

None of the following steps worked.  I tried them all and I still keep getting those marks.  For each step, the paper was inserted through the rear feeder:

1) I unchecked "High Speed" in the "Quality Options" menu thinking that the marks may not appear if the ink has a little more time to dry.

2) I changed the platen size from "Standard" to "Wide" thinking the Harman paper is thicker than the Epson paper and, therefore, pressing against the rollers.

3) I used Level 5 (SuperPhoto 2880 x 1440 dpi) for Print Quality.

3) I created a Custom Paper Configuration (Manual at page 41) with these settings:

• Platen: “         Standard as Epson suggests
• Thickness Pattern:     3 but it was hard to know what to select. The lines that are printed are faint 
            and small. So it is very difficult to see the gap between the lines to
            determine which setting number to select.
• Paper Feed Adjust A and B:    I made no settings because I'm not getting any banding.
• Drying Time:       I picked 10 seconds (so that there is plenty of time for the ink to dry).

Before taking the above steps, I tested with 11 x 14 Epson Glossy Premium paper and inserted it through the rear feeder -- and there were no marks at all.  I'm using the Harman paper because Epson does not make the 17 x 25 size.

Before doing so, I thought I would post and ask for the settings others are using or for any other tips or advice.

Epson tech support's immediate response is to blame the Harman paper. 
There must be a simple solution that I or Epson tech support is overlooking.

[jrsforums]

Harman Gloss baryta is 0.37mm thick, so you need a setting of '4'...at least.

I would also suggest a platen gap of 'wider'

The black or white gaps sound like a feed problem....maybe caused by you thickness setting.

Be careful of paper curvature.  The 3880, like the 3800, does not have a paper suction and he Harman is a bit prone to some curling.

John

[Diamond Star Halo]

Thanks so much for that suggestion John.  The combination of thickness at 4 and platen at wider has produced the best print so far.  I still have to look at it more carefully, but I'm not seeing any marks now.  Rolling the paper ends with a long shipping tube also seems to help. 

The only remaining issue is that the narrow unprinted borders around the image are not proportional.  The left side is about a 1/16 or 1/8 wider than the right side.  So the image is slightly off-center.  This has been happening consistently and is not the result of the settings you suggested.

I've checked Center Image box, the Scale to Fit Media box and various combination of checking and unchecking either or both.  I've even manually entered numbers in the "Left" box so that the image appears centered in the preview.  No matter what, the image is always off center.  The image was not cropped, so it's not like the aspect ratio changed (though I'm not sure that would make a difference).