Lines on baryta papers

[mrcmrc]

Hi guys,
I need some help... on my Epson 3880 I often print on Canson Baryta paper, with no problems. Now I've print a BW picture on a A3 sheet (the photo is landscape oriented), the sky of the photo is very light gray (almost white). I see in the sky some very light lines (are not in the picture, of course), and cannot figure out because this is happening. I tried with an A4 sheet of the same paper, and also with the Gloss Baryta by Harman/Hahnemühle, and the lines are there. Tried to do a nozzle check and to manually set the platen gap to "Widest" with no results. Tried with a matte paper and the lines are not printed. Tried also in Photoshop to select the sky, turn it white, and print: no lines in the baryta papers...

I attach a macro of a small portion of the print, just to show the lines (in order to show them I had to darken the photo).

Any idea?

Thanks a lot.

Edit: you have to click the jpeg to get the magnified photo to see the lines...

[neile]

Are you 100% positive those aren't in your original image? I've had that occasionally with customer prints and I always get scared that something's wrong with the printer, but on very close inspection of the photo it turns out it's banding in the actual image.

Neil

[Robcat]

How are you converting to B&W and are the bands present when you print the image in color? I've had some artifacts arise in continuous tone areas when B&W conversion is followed by strong manipulations (I forget exactly what, as I rarely do B&W anymore and this was some time ago).

[uaiomex]

I'm no expert but to me it seems to a problem of the file. The lines seem to be slanted and the dots forming them are very random in position, space and size. It reminds me of some scans I've done with b&w negative with an Epson 4870. Have you tried applying EQUALIZE in PS to see if the lines show on the monitor?
Eduardo

[mrcmrc]

I'm no expert but to me it seems to a problem of the file. The lines seem to be slanted and the dots forming them are very random in position, space and size. It reminds me of some scans I've done with b&w negative with an Epson 4870. Have you tried applying EQUALIZE in PS to see if the lines show on the monitor?
Eduardo

Ops... Eduardo, I've tried to apply equalize as suggested and yes now I can see the lines in my tiff file... very sorry, before applying the adjustment the lines were not visible at all... thanks!

Many thanks also to neile (you're right, the problem is in my original image) and to Robcat (I haven't tried to print the original color version, the problem is generated by my conversion in BW).

Bye!