The author introduces loop-forms and the variables of their construction. Six possible types of loop-form are defined, and three of these types—the 3-orbit, the 2+1-orbit, and the 1+1+1-orbit loop-forms—are examined in detail. The complete form-set for each is given, and various features and subsets are discussed. Recent artworks that employ loop-forms are illustrated, and the author explains the color and composition strategies employed.