There are several kinds of paper for ordinary books in the printing industry:
1, offset paper, which is used in most ordinary books, such as textbooks.
2, coated paper, most magazines use this paper, this paper has a smooth surface and a certain gloss, suitable for printing books with many pictures, and some illustrations or insert advertisements use this paper.
If your book is mainly written, there is enough offset paper. If there are many pictures, use coated paper to display them better. Both kinds of paper can be written with a pen, but the permeability of offset paper is higher than that of coated paper, and pen ink may penetrate into the back.