what happens if you record a type I cassette on type II setting, and vice versa?

AudioGon used to be a reliable source of information…

Assuming you can set the record EQ on your deck (and it’s not automatically set via the physical notches on the cassette) it’s generally best practice to record on both Type I and Type II media using the 120us setting (also, assuming you can set the bias). 
If you really want more info, head over to tapeheads.net.