Lynn Lindstrom, age 10, of Clearfield, Penn., for her question:

HOW IS CARDBOARD MADE?

Cardboard is made by pressing several layers of paper together. Manufacturers often coat the cardboard for decoration or to improve the surface for printing.

Cardboard is the popular name given to any stiff paper or paperboard that is more than 0.006 inch thick. It usually does not mean paper used for special purposes, such as wallboard or corrugated boxboard. Various names are given to cardboard. The name might designate the final use, such as poster board or shoe board. Another type is bristol board which is used for index cards, postal cards and a wide variety of printed matter.

Other popular types of cardboard are bending board, strawboard and newsboard.