I had an interesting discussion earlier this week with Howie Fenton, a writer for GraphicArts online and also a consultant for NAPL. Howie was interested in XPS and the new Print Path but was also concerned about reports of problems when printing to PostScript devices using Type 1 ("PostScript") fonts. Howie has pointed here from his blog, so that gives me an opportunity to welcome readers from GraphicArts Online — Hello and welcome — and also to dive deeper into the areas that Howie had heard concerns about.
Windows Vista Printing to PostScript
The first area that Howie expressed concern over was printing to PostScript devices, specifically printing from the 2007 Microsoft Office System (I'll just use Office 2007) on Windows Vista to a PostScript device using documents that contain Type 1 fonts. Howie had heard reports that glyphs were being rasterized, something that would obviously make the output unsuitable for high resolution devices, including plate and image setters. This wasn't something that the Windows printing team, or the Office team were aware of, and since it would be a significant regression from Windows XP and previous versions of Office, I'd expected that we would know if there was a problem (we usually do ;-). A quick sanity check using Windows Vista, Word 2007, a collection of different font formats (including Type 1) and a variety of PostScript-based print drivers showed that the print system is generating correct and expected output; PostScript jobs with the complete font information and glyphs that haven't been rasterized.
Saving to PDF or XPS
For Office 2007, Microsoft provides the ability to save as PDF or XPS using an add-in, helpfully called the Save as PDF or XPS Add-in (download). Howie has reported that "Since then I have started to hear that the Windows PDF plug-in may not be the best way to create PDF or XPS files. These reports discuss how Type 1 fonts become low resolution bitmapped fonts when the save to XPS or Save to PDF options are used.". As I'd explained in our discussion, this is expected behavior because some fonts provide a flag that indicates they are not licensed for embedding, if a font is not licensed for embedding many implementations, including the add-in, rasterize the glyphs so that the document can still be viewed.
For example: when saving a Word document that contains a Type 1 font (or other font formats) to a PDF document using the add-in, the resulting PDF usually contains the original font information, i.e. the font glyphs are not rasterized. The reason for the ‘usually’ caveat in the previous sentence is that Word enables the user to honor the font embedding settings, by enforcing rasterization of glyphs for fonts where the licensing flag is set such that the font should not be embedded. However, for PDF output, you can override this setting using the ‘Bitmap text when fonts may not be embedded’ check box that is provided in the save as PDF options dialog.
Here’s the screen shot of the dialog:
And here's two examples, one with the option checked and the resulting text rasterized, the other with the option unchecked.
The situation with XPS is a little different. Firstly, the XPS format supports font information in only the OpenType format. This means that any application creating XPS files from content that is expressed with fonts in other formats, needs to convert that font to OpenType so it can be included within the XPS file. That's not a particularly difficult task since OpenType (a joint development between Adobe and Microsoft) supports both PostScript and TrueType font data. The second difference is that in XPS fonts must always be embedded. This means that you can't rely on referencing a font in the document and having the font available on the printer (or print workflow); with XPS the font has to be in the document. This means that if a font is not licensed for embedding, text has to be rasterized — there's no option to 'hope that the printer has the right font installed'.
One last thing
Howie quoted me as saying “Type 1 fonts should get converted to Open Type fonts and become embedded. He said if that is not occurring then there is a bug and they will fix it.". The comment regarding Type 1 fonts being converted to OpenType is in the context of creating XPS files (see description above), it does not apply to creation of PDF. Also, my comment about bugs was a more general one — we want people to be able to print, if there are problems we'd love to hear about them!
[PS Thanks to Cherie & Rush on the Office team for talking the time to double check]
[20070923 fixed links]