I was asked today about the difference between sans-serif and serif fonts, and if it is possible to convert one into the other.
This article gives a lot of information about fonts and is a great starting point. http://en.wikipedia.org/wiki/Serif
These fonts below are considered ‘web safe’ – i.e. they will work on the vast majority of computers and devices without looking weird. As you can see, some are serif, and some are san’s serif.
A font is either generally either serif or sans-serif, you can’t just flick a switch to change it from one to another.
Mixing the two is generally not a great idea – it makes the website look messy. Choose one or two, and stick with them through your site.
You may be seeing a blank order printer screen when you go in to the app. The good news is that it isn't broken, your browser just needs more permissions.