Striped halftone printing

[JstnPwll]

I am using a code library (https://github.com/devongovett/pdfkit) to generate PDFs for printing. When I got my PDFs printed, some of the lighter colors had extremely noticeable striping in their halftones. I'm attaching an image example. The guy helping me at the print shop said there's nothing he can do on his end to make those go away, but that the printer is state-of-the-art and that there's something wrong with my PDF.


So my question: is there a setting or a mode that needs to be adjusted in my PDF file to correct this? I tried searching Google for PDF & halftone topics but I didn't find much.

 

[Dov Isaacs]

You attached a JPEG file, not the PDF file. Without the PDF file, there isn't anything we can do to analyze what's going on and assist you in any way. Sorry!

- Dov

 

[JstnPwll]

Yes, I wanted to demonstrate the problem I get when I print; the PDF renders fine onscreen. I was hoping someone knew enough about the PDF spec offhand to say whether this sort of print pattern is affected at all by known PDF output settings.

I can't attach the PDF in question since it contains personal information, but I will generate a different one to upload.

 

[JstnPwll]

Here is a PDF file generated in the same fashion as the one I had printed.

 

[pabney]

Although my picture taking skill need work, the file printed fine for me on my C1000.

 

[cementary]

Here is a PDF file generated in the same fashion as the one I had printed.

There is nothing wrong with your pdf. But i've got a question — why did your printer choose line halftone pattern instead of e.g. circle dot?

 

[Dov Isaacs]

Actually, Acrobat Preflight does show a problem with the PDF file itself in terms of the embedded font. The CIDToGIDMap is invalid. But there are no images in this sample you provided, just text and vector objects.

Generally speaking, though, one normally never specifies any halftone patterns in a PDF file or even at the RIP except for very specialized work.

- Dov

 

[cementary]

Actually, Acrobat Preflight does show a problem with the PDF file itself in terms of the embedded font. The CIDToGIDMap is invalid. But there are no images in this sample you provided, just text and vector objects.

Generally speaking, though, one normally never specifies any halftone patterns in a PDF file or even at the RIP except for very specialized work.

- Dov

But there is no custom halftone info in the pdf itself — so line is obviously a printer's choice. Line "dot shape" is very bad idea for this kind of work.

 

[JstnPwll]

There is nothing wrong with your pdf. But i've got a question — why did your printer choose line halftone pattern instead of e.g. circle dot?

This was the info I needed, thanks. I'm not sure the guy who printed this for me was aware that he chose the line pattern, and I didn't know enough about it to request a different pattern. Based on what he told me I assumed something was wrong with the way I generated the PDF file.

 

[Macmann]

I printed out on our office printer-Sharp 3140-came out with stripes just like your jpeg file. Odd.

 

[cementary]

This was the info I needed, thanks. I'm not sure the guy who printed this for me was aware that he chose the line pattern, and I didn't know enough about it to request a different pattern. Based on what he told me I assumed something was wrong with the way I generated the PDF file.

Probably he wasn't. The biggest problem of today's printing industry is that people who work there actually think that pushing the "print" button is all that they need. And, of course, blaming customer for their own dilettantism.

 

[namelessentity]

Prints fine on our ImagePress c750. I would guess that your printer doesn't know he can change his halftone options from line to dot, so he just assumes it's always a file issue when this happens.

 

[Puch]

Nothing wrong either with the file or the print guy. Actually our service techs suggested us to use line screen for jobs where small type or flat areas of (not 100 percent ink covered) graphic are present. It indeed help us to handle large blocks of 50% K on our Konica C1085.

 

[cementary]

service techs suggested us to use line screen for jobs where small type or flat areas of (not 100 percent ink covered) graphic are present. It indeed help us to handle large blocks of 50% K on our Konica C1085.

Line screen for small type? Seriously?
Large blocks of 50% K is good point, if they aren't rotated.