Mixed media, in visual art, refers to an artwork in the making of which more than one medium has been employed.
There is an important distinction between "mixed media" artworks and "multimedia art". Mixed media tends to refer to a work of visual art that combines various traditionally distinct visual art media. For example, a work on paper or canvas that combines paint, ink, and collage could properly be called a "mixed media" work - but not a work of "multimedia art." The term multimedia art implies a broader scope than mixed media, combining visual art with non-visual elements (such as recorded sound, for example) or with elements of the other arts (such as literature, drama, dance, motion graphics, music, or interactivity).
When creating a painted or drawn work using mixed media it is important to choose the layers carefully and allow enough drying time between the layers to ensure the final work will have integrity. If many different media are used it is equally important to choose a sturdy foundation upon which the different layers are imposed. An old rule good to remember is "Fat over lean." In other words, don't start with oil paints. Plan to make them the final layer.
Many interesting effects can be achieved by using mixed media. Often, found objects are used in conjunction with traditional artist mediums, such as paints and graphite, to express a meaning in the everyday life. In this manner, many different elements of art become more flexible than with traditional artist mediums.