Bosse wrote: > I have a scribus document and it will be exported as a PDF and send to a > printing company (they actually prefer pdfs). They also have their own icc > profiles which I use in Scribus.
Wow. There had to be one of them. As a side note, today I did some testing on my work's print shop's ICC profiles, and found that the profiles supplied by the company my work used to use are actually a better match for the new current print shop's press than the ones that print shop supplies. Sad, really. When I configure Acrobat to treat untagged CMYK data as being in the new print shop's colour space, then preview the PDFs (untagged CMYK data) in Acrobat, everything looks good and looks how it was designed. Totally unlike how it prints. If I then set Acrobat to treat untagged CMYK as being in the old print shop's colour space and preview the PDFs, the on-screen appearance closely matches how it actually prints. In other words, the print shop's supplied colour profile is so bad that the results from their press are vastly better simulated by the ICC profile of a another printing company. My point? Just because the print shop has a profile, doesn't mean it's any good. Print shops sometimes supply generic profiles from the press manufacturer or even just a renamed SWOP or Euroscale profile. After all, proper press calibration requires expensive gear and some knowledge about colour (or the money to pay someone who has it). Sending the user a generic profile is OK (but not ideal due to gamut issues) if your RIP does a CMYK->CMYK conversion to the press's real colour space ... but my work's printer won't be the only one who doesn't do so. If you're beginning to think you can't win and should just go back to demanding dummies from the print shop before approving any work, you're probably not wrong. One day maybe most print shops (rather than just the _good_ ones) will have a good enough grasp of ICC colour to get it right, but knowing the usual rate of progress I give it ten years plus. > I want to get it as right as possible from the beginning and my question is: > > How reliable is print preview and the document I see in Acrobate reader when > it comes to colour accuracy? What OS are you using? On Mac OS X and on Windows, if you have profiled your monitor & loaded that profile into the OS, it should provide a pretty accurate preview for PDFs that contain embedded colour profile information. If the PDF doesn't contain colour profiles it can still do a good job, you just need to have the profiles used in the PDF and to do a little more setup. You have to set Acrobat / Acrobat Reader's colour preferences up so that the CMYK and RGB working spaces match those you have used in your PDF. For example, if Scribus is set up to use SWOP Uncoated as the CMYK working space (which you do not override during PDF export) and you want to preview a PDF from Scribus then Adobe Reader should be set to use SWOP Uncoated for the working space too. On Linux, Adobe Reader offers limited or no colour management. It is unlikely to provide reliable previews. I've never been happy with the results under Linux for PDFs that use anything but the RGB monitor colour space . > I tried all the PDF standards (I don't know yet > if they accept all of them) and they all look really good on screen and so > does the printing preview. Ask your printer what they want. If they have supplied a colour profile, they probably want pre-converted CMYK colour, in which case the usual "Printer" export target in Scribus should be fine so long as your CMYK working space is set to their colour profile. Ask them to make sure. Most printers want PDF 1.3 or PDF 1.4 . Your printer can tell you which, so ask them instead of guessing. If they want PDF 1.3 then, due to scribus's lack of a transparency flattener, you will have to avoid using transparency in your design or use one of several somewhat cumbersome workarounds. If they will accept PDF 1.4, that's much nicer. Few printers accept PDF/X-3 , the only other significant option. As Scribus currently handles it, PDF/X-3 quite often (always?) contains tagged RGB data. If your images are tagged with correct profiles or are in the same space as the working space set up in Scribus, the print shop's RIP should be able to convert the PDF to CMYK (or whatever they need) as well as or better than you can. Many print shops, however, do not accept PDF/X-3, either because their RIPs cannot handle it or because they do not know they can. They'll often reject it just because it contains RGB data (even though tagged RGB is *perfectly* *fine* for print). > I also wonder about the ?solid colours? option under ?color management?. The > icc profile from the printing company is not available there, is this how it > should be? I'm really not sure about that. I've never been clear on why Scribus separate this from the normal working spaces. > I am also not sure what to do with ?solid colours? when exporting pdfs > (colour tab). > > I assume ?Colour? --> ?Images:? --> ?Use ICC Profile?, means that > Scribus uses the profile I chose in CMYK pictures. Is that correct? If I recall correctly that option name is very badly misleading. I cannot remember exactly what it actually does, only that I was very surprised by the results. The tooltips might explain in more detail, so try moving your mouse over the option and waiting a few seconds. (I can't check now since the machine I'm at doesn't have Scribus and can't have it quickly & easily added). > That > profile is also embedded in the image from the beginning. If not what is the > difference here between an image and a picture? In general the two words can be treated as equivalent when dealing with computer software. -- Craig Ringer
