Actually, InDesign documents aren't just RBG or CMYK. They have "working space" profiles for both.
But images in the document can be RGB or CMYK.
If you're printing to a desktop printer, the printer will do the conversion from RGB to CMYK.
If you are sending to a commercial printer, choose File > Export > Adobe PDF and choose PDF/X-1a as a PDF preset. The RGB images will automatically be converted to CMYK.
Actually, if you are sending to a commercial printer, you need to do a bit more than just select PDF/X-1a.
For one thing, may printers now prefer PDF/X-4 which preserves all the colors and embedded profiles and allows them to to the color conversions in the RIP, and if you are not preserving colors, you need to find out what the correct output profile for the printer actually is. You also mentioned transaprency, and if the printer can handle live transaparency, it's preferable to send a non-flattened file rather than PDF/X-1a which flattens transparency. PDF/X-1a is a lowest common denominator standard that is more or less guaranteed to get you a print, but not necessarily the best print possible from your file.
@Peter Spier- So it sounds like to me PDF/X-4 is the newest PDF file type so my best bet would be to use that one?
I'm still new to the whole printing side of things so I have no idea if my colors are preserved or not. I just picked colors from the swatches, haha.
Can you break this down a bit for me ( a newbie) so that I can understand what's essential for me to do and how exactly to do it? It'd be much appreciated.
All I know is that the PDF/x-1a showed all the layers in the PDF and printer which I was extremely happy about and now I find that I am using an older version and have no idea how to get up to speed so to speak. I got a lot of what you said but it's still giberish to me being new in this.
Thanks for any and all help.
It would benefit you tremendously to get Sandee Cohen's InDesign Quickstart guide. There's considerable things to know about setting up a document for print as opposed to web, and her book will definitely be the way to learn.
@HeyMikey- Thanks for the book recommendation. I really appreciate it! I'll have to check it out.
Most commercial printing is done using either "spot" color inks, which are like pigmented paints where you (mostly) don't mix them together, or with so-called "process" color inks (CMYK) which are used printed as dots next to each other in various densities and they fool the eye into seeing a broad range of other colors. Logos are typically dsigned as spot colors, photographs must be printed with process. Desktop printers mostly all use CMYK inks (some specialty photo printers add some other colors, or light or dark versions of one or more of the CMYK inks in order to get a better ink balance on the paper), but printing presses can use either. Each ink on a press requires it's own plate, so it should b clear that for a job that has only one color a spot ink will be less expensive to print thatn a 4-color mix that "looks" like the spot color, and edges will be sharper, too.
Every output device has certain color characteristics associated with it that depend on the ink set and the paper. These characteristics are the "output profile" for that device under the given print conditions. These output profiles are generally "device dependent" and it's rare (think unicorns rare) that an output device has the ability to reproduce a broader range of colors than you've captured in your original image, or even a range nearly as large in the brighter tones. Once you've made a conversion to one of these output profiles you've made a permanent alteration to the colors in the file -- you can't go backwards and recover colors that you've lost -- so it is important to knwo the correct output profile before doing the conversion.
Your images are typically captured as RGB, and even a small RGB space like sRGB is larger than the "gamut" or color range of a press and most desktop printers. In order to print the colors need to be converted someplace in the workflow to CMYK. You can do that before placing the files in ID, but that presumes you know in advance what the output conditions will be, and you can't easily multi-purpose such a file for differnt output conditions, or you can do it during the export to PDF (and PDF/X-1a requires you to choose an output profile), but if you don't know the correct profile you will not get optimum color reproduction, or you can let the printer's equipment handle the conversion. Desktop printers expect RGB data and use proprietary conversion internally, or your commercial printer can take your file with the preserved colors, as long as what those colors should look like is known (the source profile is embedded and preserved). PDF/X-4 is a standard that makes no changes to the colors in your file and embeds the source profiles for the printer to make the conversions downstream, and it leaves any transparency live in the file as well. It's not the only way to do this, but it's probably the easiest. If the the printer will accept PDF/X-4 it's a pretty good workflow (but ALWAYS ask for a proof). If the printe4r insists on a pre-converted or flattened file, make sure you ask for the correct profile, or a PDF .joboptions file to use for conversion.
Is that any clearer? Color management is a huge and complex subject to try to explain in a forum environment.
@PeterSpier- Thanks for taking the time to help me understand color management. I still have a lot to learn but this is a good start! So thank you!