A form is an artist's way of using elements of art, principles of design, and media. Form, as an element of art, is three-dimensional and encloses space. Like a shape, a form has length and width, but it also has depth. Forms are either geometric or free-form, and can be symmetrical or asymmetrical.
Geometric shapes are precise edged and mathematically consistent curves, they are pure forms and so consist of circles, squares, spirals, triangles, while geometric forms are simple volumes, such as cubes, cylinders, and pyramids.3 They generally dominate architecture, technology, industry and crystalline structures.
In contrast, organic shapes are free-form, unpredictable, and flowing in appearance. These shapes and organic forms visually suggest the natural world of animals, plants, sky, sea, etc... The addition of organic shapes to a composition dominated by geometric structures can add unpredictable energy.4
A positive shape is a shape, that has details inside it, such as an outline of a human, with body features. Contrarily, a negative shape is a shape without any details; it's just an outline.
A shape that is representative is created by the flattening out of three-dimensional objects. 5 Nothing is actually geometric, but can be interpreted as such by breaking it down to shapes that, when put together, form a recognizable silhouette.6
"NIU School of Art Vocabulary". Archived from the original on 2004-06-24. Retrieved 2008-12-15. https://web.archive.org/web/20040624191040/http://www.niu.edu/art/foundations/site/Vocabulary.htm ↩
Stewart 2006, p. 381 - Stewart, Mary (2006). Launching the imagination : a comprehensive guide to basic design (2 ed.). New York, NY: McGraw-Hill. ISBN 0-07-287061-3. OCLC 58422580. https://search.worldcat.org/oclc/58422580 ↩
Stewart 2006, pp. 378–384 - Stewart, Mary (2006). Launching the imagination : a comprehensive guide to basic design (2 ed.). New York, NY: McGraw-Hill. ISBN 0-07-287061-3. OCLC 58422580. https://search.worldcat.org/oclc/58422580 ↩
Stewart 2006, p. 32 - Stewart, Mary (2006). Launching the imagination : a comprehensive guide to basic design (2 ed.). New York, NY: McGraw-Hill. ISBN 0-07-287061-3. OCLC 58422580. https://search.worldcat.org/oclc/58422580 ↩
Fisher, Mary; Zelanski, Paul (1996). Design Principals and Problems. San Antonio: Harcourt Brace College Publishers. p. 90. ISBN 0-15-501615-6. 0-15-501615-6 ↩