... is embarrassingly poor. I've been a happy iBook/MacBook user for two years now - I'm pretty satisfied with MacOS X and the way it generally stays the hell out of my way when I'm trying to work (unlike some operating systems). I like Preview, the built-in PDF viewer, but had never tried to annotate a PDF with it until yesterday. The annotation tool gives you two options:

  1. You can draw a thick-lined red oval around a region of the document to which you want to draw attention. You can add no accompanying text or explanation so you must leave it to the reader to guess your intention. You can't change the colour or thickness of this oval either. Color is less of an issue - thickness definitely is - it's impossible to adequately encircle individual words for example.
  2. You can insert a thick-lined rectangular text-box with a fixed, yes fixed font - which is way larger than a typical document's font. I found myself trying to annotate a paragraph with the six words I could fit into the available space.

Eventually, I just gave up (I was sitting on a train with no network access) Later on, having searched online, I found this article in MacOSX Hints, which points to Unsanity's Silk which apparently allows the annotation font size to be changed at least. Various comments on this article point to simple 'under-the-hood' property tweaks which can achieve this also. I can confirm that:

defaults write com.apple.Preview NSSystemFontSize -int 9

does change the font size in the annotation tool to a more useful 'size 9'. But honestly, what were Apple thinking? We know they can do better than this!