Bug 134080 - PDF-exported documents set black fonts to colored fonts
Summary: PDF-exported documents set black fonts to colored fonts
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Printing and PDF export (show other bugs)
Version:
(earliest affected)
6.4.4.2 release
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: PDF-Export
  Show dependency treegraph
 
Reported: 2020-06-17 19:28 UTC by Robert Großkopf
Modified: 2021-07-28 10:17 UTC (History)
1 user (show)

See Also:
Crash report or crash signature:


Attachments
Example document, just some text (11.67 KB, application/vnd.oasis.opendocument.text)
2021-07-21 16:51 UTC, mahfiaz
Details
Printed using PDF printer with colors (turns out gray) (29.02 KB, application/pdf)
2021-07-21 16:53 UTC, mahfiaz
Details
Printed using PDF printer with grayscale (turns out real black) (29.02 KB, application/pdf)
2021-07-21 16:53 UTC, mahfiaz
Details
Color inspector on text printed as colors (24.88 KB, image/png)
2021-07-21 17:18 UTC, mahfiaz
Details
Color inspector on text printed as grayscale (25.47 KB, image/png)
2021-07-21 17:19 UTC, mahfiaz
Details

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Description Robert Großkopf 2020-06-17 19:28:46 UTC
This bug is reported in German LO-user-list the second time.

Create a new document. Write Text down and fill one page by copying. All the characters must be black.
Export this page to MyDoc.pdf
Start 
gs -q -o - -sDEVICE=inkcov MyDoc.pdf
on konsole.
It will give something like
0.10067  0.10067  0.10067  0.10067 CMYK OK

Cyan, magenta and yellow are also part of the document. So if you give this document to a print-shop you have to pay and will get a colored print instead of a print, which contains only black.

Tested here with LO 6.4.4.2 on OpenSUSE 15.1 64bit rpm Linux
Comment 1 Juergen 2020-06-19 11:33:28 UTC
I can confirm the buggy behavior with LO 6.4.4.2 (x64) on Windows 10. If I write a text with Writer whose font color is either set to ›Automatic‹ or ›Black‹ and then create a PDF file from it, the apparently black text is not black, but is rasterized in RGB colors.
Comment 2 mahfiaz 2021-07-21 16:50:49 UTC
This bug bothers me as well. It has been around forever. This causes black text to be ~90% black when printed from PDF, which is mostly visible from jagged edges of characters, makes a 600 dpi printer look like 150 dpi.

For a workaround you can print to PDF, choose "Grayscale" colors from printer options. In this case a PDF with text as CMYK black turns out. This obviously works only with grayscale documents.

I will attach example PDF files and also corresponding color inspector screenshots from Adobe Reader Professional.
Comment 3 mahfiaz 2021-07-21 16:51:59 UTC
Created attachment 173751 [details]
Example document, just some text
Comment 4 mahfiaz 2021-07-21 16:53:00 UTC
Created attachment 173752 [details]
Printed using PDF printer with colors (turns out gray)
Comment 5 mahfiaz 2021-07-21 16:53:39 UTC
Created attachment 173753 [details]
Printed using PDF printer with grayscale (turns out real black)
Comment 6 mahfiaz 2021-07-21 17:18:39 UTC
Created attachment 173755 [details]
Color inspector on text printed as colors
Comment 7 mahfiaz 2021-07-21 17:19:31 UTC
Created attachment 173756 [details]
Color inspector on text printed as grayscale