Elements of Design Straight Lines This steel beam is an example of straight lines in design because it gives the steel beam definition, and a feeling that the beams are extremely stable. The straight lines make this design seem better because It adds a nice detail and allows you to know that this object is in fact made out of steel. Curved or Jagged Lines The pillow is an example of curved lines in design because it makes the pillow look soft in the drawing. The curved make this design seem better because it adds very good detail to the drawing giving it a very realistic feeling. Heavy Lines