Recent posts

#91
Layout Issues / Re: 3 fold brochure
Last post by utnik - March 12, 2023, 11:58:06 PM
Quote from: know473 on March 12, 2023, 05:53:40 PM...The graphic designers there use Adobe software, so I want to avoid discussing the underlying source file.
even then i would ask the print house how they would like the fold marks in the .pdf file. (it could be a hairline in a spot color called 'fold' or something like that...)

utnik
#92
Beginner Talk / Re: Color management: colors o...
Last post by utnik - March 12, 2023, 11:51:21 PM
hi jo

Quote from: J0j0 on March 12, 2023, 02:47:38 PM...help me understand what would be considered `extreme green or blue corners of the rgb space'?
this should be done with ale's post.

Quote...there are a few colours that are neither dark nor red tones (in HTML notation: f6ec3c, 27bcb2, 5eccf2, 45b75c and 83d4f3). If these fall into the `extreme green or blue corners of the rgb space' category, how could I deal with this - would I necessarily require colour proofing or are there alternative approaches?
well, they are not really 'extreme', but when you look at the second color scheme in ale's post, you'll see that they are around the edges of the cmyk space.
if you fear a color issue and don't trust your screen (mine is very roughly calibrated, but it works for my needs...) you should really ask for a proof.

Quote...I would like to avoid significant loss of contrast or colours that do not make sense in context, such as a green sky.
the loss of contrast will be there. the cmyk model of the printer can't handle the same contrast as your screen. but complete color changes shouldn't happen with the colors you listed here.

utnik
#93
Beginner Talk / Re: Color management: colors o...
Last post by a.l.e - March 12, 2023, 06:46:00 PM
hi jo

you might want to have a look at

https://en.wikipedia.org/wiki/Color_space

and more specifically to



https://en.wikipedia.org/wiki/Color_space#/media/File:CIE1931xy_gamut_comparison.svg

or



https://en.wikipedia.org/wiki/Color_space#/media/File:Colorspace.png

(the second one is more what you want, but it's not so nice...)

some colors are not common to all the RGB spaces (the screen colors) and many colors of the RGB spaces cannot be represented in CMYK (the printer colors).

ciao
a.l.e
#94
Layout Issues / 3 fold brochure
Last post by know473 - March 12, 2023, 05:53:40 PM
Hi there,

as a complete newbie to fold brochures I want to create a 3-fold roll brochure to be printed by a professional printhouse. I want to provide them with a pdf file. (The graphic designers there use Adobe software, so I want to avoid discussing the underlying source file.)

I would create a Single Page type of document with 2 pages in Scribus (my version is 1.5.7) and arrange the content in 3 panels per page as depicted in the attachment.

What I do not understand is, how to include "folding marks" of "folding guides" or however it is called (I do not know the right expression) so that the printhouse knows where to fold. I want to control their exact position as the panels may not be equal size etc.

(Maybe I should mention that I also tried the Facing Pages type of document just to see how it works in Scribus, even though there is only the half fold option with 2 panels next to each other. As a result, it exported every panel as a separate page with bleeds. I expected it would export 2 pages with 2 panels per page and bleeds around each pair of panels.)

Many thanks!
#95
Beginner Talk / Re: Color management: colors o...
Last post by J0j0 - March 12, 2023, 02:47:38 PM
Hello utnik,

Thank you so much for your reply, this was very helpful - I somehow did not realise that the colour management is intended to take care of out of gamut colours as well.

Could you please help me understand what would be considered `extreme green or blue corners of the rgb space'? I understand this as meaning that the G- and/or B-value of the RGB exceed a certain threshold (e.g. anything with G- and/or B-values above 240 on a [0,255] scale).

I checked all images in my file: colours out of gamut are indeed mainly dark colours, however, there are a few colours that are neither dark nor red tones (in HTML notation: f6ec3c, 27bcb2, 5eccf2, 45b75c and 83d4f3). If these fall into the `extreme green or blue corners of the rgb space' category, how could I deal with this - would I necessarily require colour proofing or are there alternative approaches?

It is actually hard for me to tell how important color management is for this project - I did not create the images and my screen might not display them exactly as the author intended them, so I do not insist on exact shades. However, I would like to avoid significant loss of contrast or colours that do not make sense in context, such as a green sky. Since I've run into similar colour issues with a print project before, I'm now trying to do better...

Best
- jo
#96
Bitmap Images / Re: Warning after inserting an...
Last post by vadv55 - March 12, 2023, 09:09:27 AM
I am very grateful to you for detailed answers. Now I will look for the necessary settings to manage them.
#97
Raster and Vector Graphics / Re: Errors with PDF Import - w...
Last post by AdmFubar - March 12, 2023, 07:56:52 AM
Might be... but more likely it is a pdf that isnt created to spec. Have you opened the pdf in a text and or hex editor? You can view the pdf "innards" that way and get a better idea about how they were created.
#98
Beginner Talk / Re: Color management: colors o...
Last post by utnik - March 12, 2023, 07:48:15 AM
hello jo

depending on your images, this may not be an issue at all.
the 'out of gamut' warning just tells you, that this part of the image will be adjusted to match the export profile.

for images you normally select 'perceptual' as the rendering intent. that means, the whole color range will be adjusted to the range of the output profile in a way, our eye will (more or less) just detect the reduced contrast.
for graphics it is in most cases 'relative colorimetric' – even here the full color range will be adjusted to preserve local contrasts as good as possible.
but there are at least two situations where you should deal with this 'out of gamut' warning seriously.
  • if it is not just about a darker tone, but about a color out of the extreme green or blue corners of the rgb space, which will really look different (in the red corner the difference is smaller...)
  • in cases where graphical elements need to match with parts of an image (here you have to deal with your colors and the color management in an advanced manner...)

otherwise let do the color management its job (it will take care of the ink coverage and the color conversion to the output profile...) then take a look at the exported .pdf file and decide if there is some need to adjust anything.
if your work is color sensible, you should consider a good print proof anyway. (contact your print shop.)

utnik
#99
Raster and Vector Graphics / Errors with PDF Import - what ...
Last post by adrianstephens - March 12, 2023, 07:24:59 AM
Hello all,
I've just set my first 68-page community magazine using scribus.
We have about 60 ads.  Artwork generally arrives in pdfs.
With about 20 of these,  I've had to rasterise them in Inkscape or GIMP because of import
errors with pdf.

The errors include:  mishandling of a gradient transparency over an image,  loss of
shape details,  missing line of text,  background appearing in supposedly transparent text.

I'm wondering if there is a specification for the PDF version that scribus can import, and the files I'm importing are not meeting this spec.    Otherwise a ~30% failure rate does seem surprising.

Regards,
Adrian Stephens, Cambridge UK
Former technical editor, now mostly retired
#100
Beginner Talk / Re: Color management: colors o...
Last post by J0j0 - March 11, 2023, 08:57:50 PM
Thank you for the quick response!

I tried brightening an image within Scribus with Image Effects, however, as a result, the "out of gamut" marker colour was brightened as well ... I totally did not expect this.
outOfGammut.jpg outOfGammut_bright.jpg 


I can of course edit each image in Gimp, though I'd prefer not to (does Gimp preserve the embedded colour profile? I vaguely remember having issues with creating images with non-sRGB colour profiles in Gimp before)

I also played around with rendering intent, but none of the given options resolve the out-of-gamut issue.