When you open a PowerPoint or Keynote file, any custom font not installed, will automatically be replaced by your operating system. The first choice you have to make, is whether to use custom fonts or stick to the standard ones installed on your computer. If not, its important you make a number of educated decisions regarding fonts. If you are bound by a corporate presentation template, where font use has already been decided for you, skip this section and move on to the next chapter. Fonts greatly impact the look and feel of your presentation.