One size doesn't fit all! Many learners are growing increasingly comfortable working with digital text. They use highlighting and annotating tools with ease and aren't tempted by online distractions. Other students notice that they are better able to manage their learning using print materials. Typically copyright or licensing restrictions prohibit printing the full text of commercially published or library licensed ebooks. But there is good news for users of online open educational resources.
The usual restriction on copying the full text of a copyrighted work in its entirety doesn't apply to open educational resources (OER) because they are licensed with Creative Commons (CC) licenses which specifically give permission for coping and distribution of the work. (Some CC licenses prohibit commercial copying and distribution, but if you are a student that is interested in securing a print copy of an OER textbook for your own use this is not a commercial use and doens't apply to this circumstance).
This page lists alternatives for obtaining print copies of OER textbooks.