40 Chapter 3
Section Lines.
Section lines (also called cross-hatch lines) indicate the cut surface in a section view. They usually con-
sist of fine linework (thinner than object lines), typically angular (45 degrees), giving a tone to sectioned
surfaces (Figures 3.4A and B. Section lines are used to emphasize the cutting-plane surface and make
the view easier to visualize.
Center Lines.
Center lines consist of thin (light), broken lines of alternating long and short dashes. They are used to iden-
tify the centers of symmetrical objects such as a column, wall, or window. Center lines are also used to in-
dicate the center of a whole circle or part of a circle and to show that an object is symmetrical about a line
(Figures 3.5A and B). The symbol is typically drawn as such: (C/L). Center lines are symmetrical on the
axis of circular features and are also used to locate centers of windows and door symbols on floor plans.
Figure 3.2 Object lines identify and describe the shape of an object. For example, in this drawing object lines
are used to portray the furniture as well as the various architectural elements in the design (e.g., stairs,
elevators, walls, etc).