I am not filled with confidence from the quotes from your print service provider.
Adding margins and bleed in itself does not require a colour space conversion – however it sounds like this is part of a wider site specific workflow where a CMYK conversion to the local “house” CMYK profile will take place.
With the right software, people safely convert from different CMYK conditions all day long. With the wrong software, solid black or black only tinted content would be converted to CMYK and not remain K only.
The colour mode/model may be RGB, however that is not a colour profile. A colour profile would be descriptive, such as sRGB or Adobe RGB etc. So can your “service provider” work with any RGB colour profile/s – or do they only support content in a specific assumed colour profile?
PDF/X standards all require a CMYK output intent, even if the content is RGB. However, InDesign will change a forced RGB conversion to CMYK if one attempts to set a CMYK output intent. This may mean that the best place to work with colour is not in InDesign, but in Acrobat Pro or other PDF editing software.
Further to my previous reply:
* What exactly does your PSP require? A PDF which has CMYK text and other content, but all raster images in RGB? Or do they require a PDF with all content RGB, text, imges, vectors etc all in RGB, no CMYK or grayscale content whatsoever.
* What exact RGB colour profile do they require (sRGB, Adobe RGB) – or can they work with any ICC tagged RGB without assuming or making a mess of colour when converting from RGB to CMYK?
I would feel more comfortable making suggestions once these unknowns are answered. Of course, your PSP should be the one providing specific step by step instructions, you should not have to try to second guess their requirements by crowd sourcing advice on internet forums in lieu of them providing required information.
Thank you for your reply.
I agree the addition of Bleeds and Margins does not require colour space specifics, but this company concerned, and like a few others in the marketplace specialise in on demand printing, which entails them forwarding the document to the printer partner who is closest to the recipient requesting the on demand print. This means that many printers have individual requirements based on their own unique set up.
The official line I have been given says that they wish to receive a flattened pdf PDF/X-3 with an RGB profile which will later be converted to CMYK, the settings for which will be defined by the printer conducting the work.
Unfortunately, i do not know at this moment which RGB profile should be used for the submitted PDF in order to retain the colours in my original document.
please see my answer to your initial response for clarity
More clarity would be good :]
Do you have Acrobat Pro? Colour conversions from InDesign don’t provide any great control. I would prefer to work from the PDF file if at all possible.
Can you ask them for further detail?
* What ICC profile? sRGB would be a lowest common denominator, however if they assume Adobe RGB and ignore your sRGB profiles then your colour his screwed (same for providing Adobe RGB and they assume sRGB). It should not matter if their colour management is setup correctly, however I have seen too many PSP that ignore embedded profiles and assume, which is not good for RGB input.
* What CMYK profile should be set as the output intent of the PDF/X-3?
* Do they wish for the entire PDF to be RGB, including solid black text as say 0r0g0b rather than 0cmy100k? Or do they wish for only the raster image content to be RGB with the rest of the text and vectors in CMYK? You may need to provide a version each way just in case if they are not going to be specific.