When I print an MO thread (using Chrome, at least), the font size is extremely small (8pt? nested indices are very hard to read, at least). Since I don't think this is easily fixable on the user side (at least not without MathJax getting all messed up), could we have a "printer-friendly" option or an export to PDF? (Of course, a script that would transform markup to LaTeX would be gold standard, but I'm not asking that much.)
As mentioned in the comments StackPrinter is often useful for such purposes.
This tool is very frequently mentioned in several other posts on this topic, sometimes various other tools are mentioned too:
- Printing out Stack Overflow/Exchange Q&As including comments? on Meta Stack Exchange
- Save the answer in PDF? on Mathematics Meta
- There are some bookmarklets created by the user NormalHuman, see: Save the answer in TEX? or Save the answer in TeX/PDF - revisioned. As mentioned in those posts, some of the links stopped working at some point in the past (so you might save the bookmarklet if you want to use them). Here is a link which seems to be working at the moment Save a question and answers as LaTeX (github). (I will just mention that there are some other bookmarklets created by the same user that might be useful for people using Stack Exchange sites. You can find source code also on github.)