Conversation so far:
what kind of paper is used in books
Most printed books, use uncoated paper stocks for the inside pages of the book, and a coated cover stock for the book cover.
what is the difference between uncoated and coated paper stocks
Coated papers are coated with glossy, semi gloss, or matte finishes. Uncoated paper does not have a coating to fill in between the fibers so it is rougher and porous
what is the uncoated paper stock used for
Uncoated stock is used for printing envelopes and business letterhead for an elegant and classy look. Examples include real estate brochures, business stationery, restaurant menus, school bookmarks, and college booklets.

Question: what is the advantage of the coated type
Self-contained rewrite: what is the advantage of coated paper stock