Spellbook familiar spell sharing between PCs

[bungs]

Hi all,
Haven't found anything in the forums about this, maybe I'm looking for the wrong conversation.

I play an investigator, and my friend plays a wizard with a familiar. Investigators can add wizard spells to their formula books.

Usually this is done by saying one reads the other's spellbook. But how does one share/copy spells from the familiar?

Thanks!

[Lelomenia]

Is his Wizard a Familiar Adept archetype, or why is the familiar relevant?

[Dave Justus]

If the prepared arcane caster doesn't have a spellbook (witch, familiar adept wizard or something else), then you will not be able to add their spells to your formula book without some other mechanism (such as the other caster having scribe scroll and making scrolls for you to study.)

If the wizard has a spellbook then whether or not they have a familiar is irrelevant to your copying spells from it to your formula book.