A world where you can enter a book by placing your hand on its pages, and leave with a linking book.

[Joshua]

The idea behind the book is that writing in a blank book ( a special kind of book) creates a world inside that book that you can enter into, but without a linking book you can never return. the main character goes underground to where a society used to live surrounded by these books, but somehow passed away. He is lead underground by his relative (uncle/father, don't remember), who has salvaged many blank books, is creating worlds out of the dead society, and is teaching it to him.

[Lobstergirl, au gratin]

When did you read it or when was it published?
Children's, YA, or adult?
Author female or male?
Remember the cover?

[0possum]

This seems similar to the Myst computer games. There was a series of books based on the game. The Book of Atrus

[Kris]

Following up on Opossum's suggestion, here is Wikipedia.org's summary of the Myst books including The Book of Atrus by Rand Miller --
https://en.wikipedia.org/wiki/The_Mys...

[Lobstergirl, au gratin]

Joshua, are you still looking for this or did you find it?

[Becca]

If it's not The Book of Atrus, it might be one of the books this list - Book-Jumping or Book-Travelling

[Kris]

Note: Joshua last active in Sept. 2019.