advice needed on tiff/pdf issue w/ POD publisher

[Sash]

I'm having a book printed via one of the printing-on-demand publishers, and the cover is black and white Line Art.

Problem is, the line art quality looks "jagged" on their proofs and I can't figure out why.

The original line art was scanned at 1200 dpi. The first tiff file I sent them was at 300 dpi (per their requested specs). They then convert it to a pdf. When it came out "jagged" they requested a higher res tiff. I sent them 600 dpi. Same result. Then I sent them 1200 dpi file. Same thing happened.

Then I just made my own pdf from the tiff using Distiller and sent them that. Same result.

When I print out the tiff file on my laser printer, it looks perfect. When I print out the Distilled pdf version, it looks less sharp (half-toney) but doesn't have the jagged line art.

wtf? Anything I can do different, or tell them to change, to take care of this?

Thanks.

[JustinHelton]

It could just be the look of the pdf on your screen...screen has a lesser dpi and cant produce the detail. I have had lots of issues with the on screen pdf looking terrible and then the print looking fine.

[Thornysarus]

Basically, when you PDF any file, it resamples all the images. Either by downsampling or subsampling depending on your images and settings.

Save as a PDF again, but tell Distiller to not downsample or subsample your images. The file size will be larger (obviously) but better that than jaggy images.

Hope this helps.

[Sash]

Thanks. I turned off compression/downsampling, and printed it out on my laser printer and it looks the same as the previous pdf printouts (unlike the perfectly crisp tiff) so I think it will likely print out jagged again with their printer.

The odd thing is that the pdf file images look really good on screen, even when viewed highly magnified.

[c0met]

Is your line art embded as a raster image in the PDF?

It sounds as if their printing system is unable to interpret embedded raster images within postscript.

Once upon a time, that was the tell-tale problem of a postscript vs. PCL print system. PCL printers would not properly interpret certain postscript commands (as they were Adobe intellectual property), particularly images like embedded EPS and would always print a lo-res preview on output despite any settings changes.

Most laser printers always had postscript support and you could even dump pure EPS files right into the printer port without software and they'd print a perfect image. Inkjets and cheaper printers couldn't do that.

If all else fails, you can take the lineart, convert it to a EPS in Photoshop and then embed that in the document rather than a bitmap. It increases file size often but assures pure postscript (usually). The PDF's built-in compression may alleviate the bloat too.