Kippenhahn diagrams of the non-rotating 2, 3, 5, and 7 M_⊙ models. The blue, green, and red solid lines show the location of maximum nuclear energy generation for hydrogen, helium, and carbon burning respectively. Energy is generated in the region delimited by the dotted lines. The red, orange, and purple plus signs show the moments of the first (2 M_⊙), second (3, 5, and 7 M_⊙), and third dredge-up episodes respectively. The black lines are isoradius lines. The initial mass of the corresponding model is indicated at the top of each panel.