I have not had the Mag printed yet and I dread the results.
To print on an offset lithographic press or a digital press, the procedure in Apple Pages is precisely the same as in QuarkXPress and InDesign.
Ask the print service what printing condition that is being sold, including what ISO 15930 PDF/X-3 OutputIntent that is used for the separation and at what resolution.
Launch the Apple ColorSync Utility, set up an Apple Quartz filter for the custom printing condition, and apply the filter when saving out from Apple Pages to disk.
http://discussions.apple.com/thread.jspa?threadID=2738092&tstart=0
saved pdfs (via postscript is better)
PostScript neither supports the TrueType / OpenType font file format, nor the ICC profile file format, nor transparency. The Adobe PDF Reference Manual version 1.3 to version 1.7 all recommend that applications save their design space directly through a PDF library, and not through a PostScript library after which the PostScript is converted into PDF.
the editor wanted to make text edits after it was layed out
InDesign and QuarkXPress each have a syntax for editing tags in plain text, although the syntax for the one is not the same as for the other. Editing tags (<tag>) have been around since before page description languages and digital graphic displays. In the late 1970s and early 1980s, editing tags were used when markup up plain text on IBM System 80 or Xerox 860 for submission to a typesetting service. ISO 8879:1986-Standard Generalised Markup Language (SGML) standardised device independent markup.
The problem with this has always been that it does not work well with page description languages, because the editors who tag the copy cannot themselves see the consequences in the frames for area composition. The line layout may reflow and the frames themselves may overflow.
Adobe InCopy was criticised at the time it was introduced because it could not show the same line layout as Adobe InDesign. So exactly what was the point? I have a journalist copy of Quark CopyDesk, but haven't tried it. I would assume that the situation is the same.
if I reduce file the resulting images are poor
The right resolution required by the RIP should be set when the image is saved from the colour correction software (Adobe Lightroom, Adobe Photoshop, Apple's digital camera software, whatever).
It is possible to include downsampling in a Quartz filter, but downsampling should not be done when the PDF printing master is saved to disk, but rather before the image is placed in Pages / QuarkXPress / InDesign. Similarly with correct tagging of the source ICC colour space to the image in the colour correction software. These conditions are the same regardless of the pagination software.
Colour is frustrating – same colour used as background and line show and print differently.
The numbers in the Apple ColorPicker specify the SAME COLOUR if and only if they reference the SAME COLOURIMETRY. The colourimetry is specified by the ICC profile that sets the source colour space, selected in the drop-down profile picker on the left in the Apple Colour Palette. This condition is also precisely the same in QuarkXPress and InDesign, or indeed in any other application that is used to submit a PDF printing master.
There are real differences, including the difference that in Pages one cannot control the rendering intent per object. The only way around this in Apple Pages is to convert photographs using the Perceptual rendering intent in the Apple ColorSync Utility before placing the photographs into Apple Pages. Remember to use the same ICC profile as will be used as OutputIntent when saving PDF/X-3 as if the source and destination profile is not the same, the separations will be reseparated which is not what one wants.
Henrik