Replying to my own question,
I found this explanation (based on OS 10.2) dated 2002 at
http://www.creativepro.com/story/feature/18131.html
PDF files created by clicking Save As PDF in OS X are based on Adobe's
PDF 1.3 and 1.4 specs. That means they're capable of supporting
transparency, and that you can add security and password protection to
your files using Acrobat 5.0. However, you cannot control any of the
parameters used to create the file -- you cannot control compression,
for example, or color space. The process does embed and subset fonts,
but it saves all colors as RGB, and PDF files created by Jaguar are
only 72 dpi. (Note: The author has since made addtional comments and
corrections on this topic. Please see "For Position Only: On Quartz
PDFs, OS X Fonts, and Light Bulb Jokes" for more information.)
As a result, clicking Save As PDF creates PDF files that are suitable
for exchanging business documents -- bids, proposals, and other
non-color-critical documents that are destined to be printed at low
resolutions (i.e., by laser printers).
[me talking, here is the correction]
http://www.creativepro.com/story/feature/18396.html
Saving PDFs, Perfected
First, I want to thank the reader who anonymously e-mailed regarding an
erroneous statement I put forth in my column last month on how to
create PDF files in OS X. At that time, I wrote that when you use the
Save As PDF button in Apple's print dialog boxes, Quartz saves all
colors as RGB, and all PDF files as 72 dpi.
Actually, Quartz generates the PDF files based on the data passed to it
by the application. If an application passes CMYK or resolution higher
than 72 dpi, then the resulting PDF file will be a high-resolution CYMK
file. Quartz does not convert RGB to CMYK, but some applications may
convert color spaces as they pass data to the PDF engine -- my tests
with a CMYK Photoshop file saved as PDF resulted in RGB PDFs
(high-resolution, however), so you have to be very careful when you're
using Apple's Save As PDF button. I still recommend (as do my sources
at Apple) that the best way to generate PDF files for print production
in OS X is to either save PostScript files and distill them in Classic,
or in Adobe applications use the Save As or Export commands to produce
PDFs for proofs, comps, and review cycles.
Me again.
This "72 dpi" stuff seems to apply to image imports. For text, it
appears that fonts and lines (most of Finale's output, for example) is
converted to PDF using the regular EPS formulae, which conserves its
resolution no matter how it is zoomed. I zoomed in on a Finale file and
a PDF created from it, and no jaggies showed up anywhere. However, I
discovered at 1000% tiny discrepancies involving stem connections,
which seemed to vary from measure to measure. Nothing of the sort was
present in the printed versions, so I assume that the tiny differences
I saw were the result of display variables, so would only appear on the
screen.
According to another article I saw, Jaguar PDFs are created at 300 dpi
by default, which is still pretty good for my laser printer, even if I
am printing images. I suppose if I was sending a book in to be
published, they might insist on higher quality PDFs with images, but if
that were the case, then I would probably invest in upgrading my OS 9
version of Acrobat 4...
So, the short answer is, yes, OSX-created PDFs are fine for sending
Finale parts to clients and musicians over the internet.
Christopher
On Oct 29, 2005, at 6:31 PM, Christopher Smith wrote:
On the subject of PDFs, I read this in the OSX-The Missing Manual.
It says that the PDFs created from the OSX print dialogue are
screen-optimised—that is, they look best on screen, but not
necessarily in print. They also said that to get them to work well in
print, you need to buy Acrobat as you did before.
This does not seem to agree with my experience, but what am I missing?
So far, I don't get some staff lines grey on screen, as I see in some
Acrobat-created PDFs.
I don't get jaggy slurs, or any other signs of low-rez, as I have been
warned about.
I don't get font substitution, as I used to get all time unless I
followed an EXACT procedure (outlined in my response to Charles).
I don't get misplaced noteheads or stems (these items used to get
nudged a bit, just enough to confuse you as to whether it was on a
line or a space.)
No complaints from clients or musicians I have emailed parts to in PDF
format.
Comparing the printout of the Finale file and the same file printed to
PDF then opened and printed in Preview, both on my venerable LaserJet
4 at 600 dpi—no discernable difference to my eye, and I was looking
hard for signs of antialiasing in print.
What could that book possibly be referring to? Hot links in PDFs?
Don't need 'em. Markup ability? Don't need it, nor was I expecting it
in the Mac's built-in PDF machine. All I wanted was good, clean, PDFs,
and I have them.
Any insights?
Christopher
_______________________________________________
Finale mailing list
[email protected]
http://lists.shsu.edu/mailman/listinfo/finale
