I would like to print them in good quality. Unfortunately, I couldn't find any of them anywhere. Are they accessible?
In addition to the SVG sprite sheets which are not quite as high-quality and a bit of a pain to work with, you can get the major site logos in EPS vector format on the company logos page. Any decent vector program should be able to convert them to SVG is that is the format you desire, but EPS is a good vector format for print.
The following logos are currently included on the page.
- Stack Exchange
- Stack Overflow
- Stack Overflow Careers
- Server Fault
- Super User