Tracing paper is a thin translucent paper for you to see through (called tracing or treles). It is effective if you design it with a synergistic effect to the next page. In addition to architectural design and drawing, it can also be used as a replacement for mouthbooks, bookmarks, or as a sticky note. It is also durable, water and oil resistant, so it can be used for packaging food, writing and so on.
(From Amazon.co.jp)