png/tif images printing with two shades of black

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Dewedi

Hey!

I'm currently working on a Halloween poster and when I decided to test print it, the background black and the black around images are two different shades on the print. However on screen it looks fine. I am using .png images turned into .tif if that helps. Using Scribus pfg makes the areas white and not invisible.

https://files.fm/u/8nzkxya6 , https://imgur.com/3HOGQGm , https://imgur.com/pOk0Y1t
On the attached pdfs test is done with Scribus print to pdf, microsoftpdf is done with Microsoft Print to PDF.

Just ask me if you need more info! Thanks in advance! :)

a.l.e

are you using the same black for both?

have you tried, using an RGB black for both the PNG and in scribus?
or the same CMYK black in the tiff and in scribus?

if you provide a .sla file, it's easier for us to figure out, how you can improve your result...

ciao
a.l.e

Dewedi

Hey! I have the .sla in the attachements! Thanks for the help :)

[attachment deleted by admin]

a.l.e

... well, of course, we need also the TIFF / PNG with the black...

i've attached a sample .sla with a rgb black and a png with the "same" black. can you try to check if you get the same black in the resulting pdf?

[attachment deleted by admin]

Dewedi

Your blacks end up as the same blacks in the print.

I uploaded 2 of the files I used here: https://files.fm/u/a26ppt4m if that helps.

utnik

#5
hi dewedi

your color management shows different settings for the color conversion for images and for solid colors ('perceptual' for images and 'relative colorimetric' for solid colors) – this is correct for most situations, but not if you need an exact color match between the two!


   edit: just checked with the images. in this case i wouldn't care about color matching – i would just eliminate the background of the images. (.tif supports transparencies...)

utnik

a.l.e

of course, utnik is right.

but if you're printing on laser printers, you don't even need the hassle of converting the png into tiff.

just use the same colors in the png and in the scribus file.

and since png supports transparencies, just make the background transparent.

from my experience, the only reason for using matching CMYK colors in both the images and scribus file is when your sending the files for profesionnal printing and the print shop requires a pdf version that does not support transparenices (or you don't want to take the risk that the print shop incorrectly flattens your pdf)

otherwise, use the same rgb blacks and/or use transpancies...
for a black file with png cliparts i wouldn't even bother to use any color management...

Dewedi

Thanks for the tips but somehow the issue still remains. On lighter background it's not so noticeable which I had to do to keep up with the deadline. However I want to know why this happens and how to fix it for future cases :)

I changed images to png with transparent backgrounds and I changed the background black to rgb.

Export to pdf gives me a weird result in printing with weird white boxes and with Microsoft print to pdf the print does the black boxes.

https://files.fm/u/e2hz2fae

The files include the sla and the 2 pngs, exported pdf and 2 print scans.