CS3 pdf export - what does this warning mean?

Question

I'm exporting an InDesign file to pdf. It's 70+ pages of black and white, no colour, one page with four grayscale photos. The Summary section of the pdf export dialogue has a warning symbol, and says this: "1) The preset specifies source profiles that don't match the current color settings file. Profiles specified by the color settings file will be used." Can anyone explain what this means, and more importanly whether or not it might impede printing?

Answer 1

I do a lot of B&W print output from InDesign, with images imported from Photoshop. There is something you should be aware of for B&W if you are printing your documents professionally or in newsprint. Sometimes your printer will be able to take your PDF in any form and make it 'fit' their process, but I've found many can't, don't, or just won't go to the trouble. They leave that up to you.
In particular, what I've found is that when printing B&W at a printer, they may use a digital printer or they may use a 4-color press (almost always more expensive due to setup, etc.). However, the PDF you prepare for them will be different for each case. Some printers will tell you that for B&W you should only have data on the K channel (the black channel in the CMYK file - they ignore the other channels altogether). If you give them a PDF with rich blacks (which will look good on screen) that is made up of all four (CMYK) colors, then it is likely that your blacks in the final print will be more like a dark grey than true black. This is because they may only use the data on the K channel and put down black in in that quantity, which might be less than 100%. If you import your images from PS as greyscale, then they should import into InDesign as a CMYK image with 100% K and 0% CMY anywhere there is black in the image. When creating your PDF from InDesign, you have to be careful about your output options too. If you choose any preset where it "Converts to Destination", then your 0 0 0 100% black will be converted and reseparted to rich black, and if the printer only takes the K channel, it won't be 100% black. I always use the Separations View in Acrobat on any PDF to ensure that any data in my B&W file is truly just 100%K with 0% CMY. (Actually, it's not quite this simple. There are a lot more intricacies involved.)
In addition, if you are sending your B&W file to newsprint, on a page where they print all four colors, then you'll want to use Rich Black. If the page you will be printed on uses black ink only, then you'll want to use the K channel only. This all sounds very complex and confusing, and that's because it is. In addition, it changes every time you change your print provider because they all use different processes, presses, workflows, etc. The safest way is to ask your printer to provide you with a .joboptions file that you can use to create your PDF from InDesign. It will have all the settings you need for their setup (although you still may have to worry about your image profiles if they assume you've included them with the profile they will be expecting, either tagged or untagged).
I've been doing this for years and it's a struggle each and every time I change anything (paper, process, 4 color vs K only, printer, press). Once you have a printer and process figured out, and have created your own .joboptions file, it takes only seconds to create a proper PDF for the job. Until that point, it is a lot of heartache and headscratching. In addition, most people I talk to at the printers I've used just don't seem to be that knowledgeable about color management, even the graphic artists that work there.