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Scribus => PDF Generation => Topic started by: jpek-m on May 29, 2015, 04:44:00 PM

Title: Gray printed bluish
Post by: jpek-m on May 29, 2015, 04:44:00 PM
I have a document witch uses only black and gray (defined CMYK 0, 0, 0, 70.2%). When I have generated the pdf file (for Print press), there is difference if I tic the 'grayscale' box in Mac OS 10.9.5 print dialog or not.

In grayscale the page prints nicely on my Samsung C460 color printer, but otherwise the gray text appear a little bluish, black text is a little blurry and printing is much slower. For example with NeoOffice there is no problem.

Is this a problem with Scribus 1.4.5? An example pdf file is attached here.

[attachment deleted by admin]
Title: Re: Gray printed bluish
Post by: a.l.e on May 29, 2015, 06:11:49 PM
i fear that the problem comes from the fact that you're using CMYK colors for a printer that is expecting RGB ones.

at some time, your CMYK gray gets converted to RGB and then, in the printer itself, back to CMYK.
(most if not all drivers for consumer printers expect RGB)

if you want a correct output, you have to use the color profile specific to your printer, otherwise you have not control on what gets printed.

still, it's a bit strange that you get a blueish gray... i would have expected some sort of brown...
but you might also have a defect (low level?) toner and the color output or your printer is not reliable.
(in my experience many consumer printers have color faults... mostly towards red or yellow...)

all in all: you should probably define your color as an RGB gray and use the correct profile for converting it, when you send it to a professional print shop that will be expecting CMYK.

good luck!
a.l.e
Title: Re: Gray printed bluish
Post by: utnik on May 29, 2015, 07:16:09 PM
i just checked the file with acrobat pro – there's absolutely nothing on the c, m and y channels. only the black channel is used in it.
so ale is right and the problem lies in the color management (or the lack of it) of your working space.

as long as your printer driver reads the color space as grayscale, it prints in shades of black, if it reads cmyk, the shades are generated with all four colors.

utnik