PDF/X-1a:2001 is a preset in Adobe Acrobat. You should be able to choose the setting from your program's print menu.
If your document was in Word, for example: File > Print > Adobe PDF > Properties > Default Settings > PDF/X-1a:2001
The preset includes all the necessary settings to meet the standard. This includes font embedding and conversion to CYMK.
Distiller is part of Acrobat Pro. You can set your default to PDF/X-1a:2001 for output, but depending upon what program you use to create your content, you will still need to verify PDF/X-1a:2001 is the setting currently in use.
I'm using Scribus to create the file, a book cover. If I understand you correctly, after installing Acrobat it will appear in the list of printers and I am to print to it rather than save or export to a postscript file first. The printshop recommends that a postscript file be created then converted by Distiller to PDF by which means I don't understand. Your suggestion sounds simpler, assuming I can select the PDF/X-1a:2001 preset from the print command.
I typically use Acrobat Pro 9 on a Windows XP system and Acrobat installs into my printers folder "AdobePDF" that functions just like a printer hooked to my computer or the network only its output is a pdf instead of paper. A screenshot of the options is below. There are other ways of creating pdf files, but this is the simplest if you are using Acrobat Pro already.
I downloaded the 30-day trial this morning and printed a cover. The menu came up as you shown in the previous message and I was off to the
races. It was necessary, however, to create a custom page size because I am printing a book cover that is in a document 18 inches wide and 12 inches tall.
I am confused by a couple of the settings, particularly the one about relying on system fonts. After creating the PDF I checked its properties and found no fonts listed. PDFs created from Scribus itself have a list of embedded fonts. Could Acrobat be treating the entire file as an image and thus does not see fonts because it I am printing to it?
Spot colors also have me confused. My document has some solid-color areas of significant size, not really large but very noticeable and important. Do I need to treat them in a special way? My images are RGB before Acrobat converts them to CMYK with the PDF/X-1a:2001 option.
I should have taken a look at Scribus before responding—Scribus does not interact with Acrobat like other programs I use do. My experience primarily involves other Adobe products like InDesign and Illustrator and Microsoft products like the Office suite, Visio and CorelDraw.
I downloaded and tested Scribus today and found that my fonts were being converted to outlines in Scribus instead of being preserved as embedded fonts. As you suggested, the resulting pdf page became an image instead of a combination of image and text and there does not seem to be a way to override this behavior (at least for the fonts I tested). The answer may be painfully obvious to Scribus pros out there, but I am stumped unless the font's license prevents embedding. For the "rely on system fonts" setting, you would almost always leave it checked. When creating a pdf, hover your cursor over the option and a description will pop up that may be helpful.
It seems like there is some confusion regarding spot and process colors. All of my needs except for certain runs of business cards would best be served with process colors instead of spot colors. Scribus has a wiki page on spot colors (http://en.wikipedia.org/wiki/Spot_color) and About.com has a page that may also be helpful (http://desktoppub.about.com/od/colorprinting/a/spotprocesswhen.htm). RGB is a color model for electronic devices, not for printers (http://en.wikipedia.org/wiki/Rgb)—what you see on your screen may or may not be close to what you would see on paper. Another color consideration would be the type of paper you will be using. There could be significant differences in color appearance when printed on coated versus matte stock, etc.
I do not have a printer here now to test how my example document pdf actually looks when printed on paper. The on-screen quality did not appear to be top quality, though I have a lot to learn about the available Scribus settings. I did change the default resolutions from screen to printer quality.
Once you have your colors worked out and just to add another pdf option into the mix: you could use Scribus' export to an eps file. After the file is created, you could right click and choose "Convert to AdobePDF". With the pdf open in Acrobat go to Advanced > Preflight > Standards > PDF/X-1a:2001 (check Apply Corrections) and save.