wa·ter·mark 
/ˈwɑ:tɚˌmɑɚk/ noun
plural wa·ter·marks /ˈwɑ:tɚˌmɑɚk/ noun [count] : a design or symbol (such as the maker's name) that is made in a piece of paper and that can be seen when the paper is held up to the light ◊A watermark is usually found in expensive paper as a sign of quality.
