Planning is the key to success in any mold making project.  In particular, areas that have deep indentations and or harsh angles, known as undercuts can pose a number of obstacles in the demolding process. Recognizing and handling these areas, and properly constructing the support shell can make even complex shapes easy to mold and cast.  The following demonstrates the brush-on mold making process on a model with severe undercuts underneath the shoulders (see figure 2.), as well as some other challenges.