TrueType hints come in the form of little programs which move the points around based on the point size and resolution. This allows the designer complete control over how the outlines react to different sizes.
TrueType Hinting
As we’ve discussed before, PDF files can contain a whole bunch of different fonts, but in the end most of them come down to two... In the early days of fonts, each glyph was stored as a bitmap at a range of sizes. Drawing it was a simple case... Everyone knows a bit about fonts, but understanding them in more detail is a bit of a niche subject. Niche subjects tend to come... TrueType hinting use a program inside the TrueType file to modify the outlines for fonts. This allows it to do clever things like optimise... 
