Why does my document reflow?

Text reflow problems, especially with applications such as Microsoft Office, have absolutely nothing to do with whether Type 1 fonts or TrueType fonts are used; rather, the problem is associated with how those particular applications request font metrics from the operating system ("absolute units" versus "at printer resolution"). Reflow problems occur with Type 1 fonts used in Microsoft Word just as often as with TrueType fonts. Applications such as FrameMaker, InDesign, QuarkXPress, PageMaker, Ventura Publisher, etc., do NOT reflow with either Type 1 or TrueType because they properly request and obtain the font metrics in a resolution-independent manner.

Related topic

Where do fonts come from?