To add a single-layer material, choose Single Layer Material (

) from the global 
Materials node’s context menu or the 
Layers submenu on the context menu of a 
Materials node in a component. Then, a 
Material node is created with some additional settings (see 
The Settings Window for Material) and a 
Shell property group (see 
Geometric Properties (Shell)) with a default thickness of 10
−4 m. You can also switch an 
Material node into a single-layer material by adding a 
Shell property group and define a thickness, and it can also turn into a single-layer material when you specify a value for the requested thickness in the 
Material Contents table, which appears when a layered shell feature requests the material properties from a standard material. The thickness for a single-layer material can be defined as a numerical value, a parameter, or an expression. Such an expression can, for example, be a function of the coordinates so that a surface with variable thickness can be described.