Constant Offset
Use the Surface Offset command to create new sheet bodies, each with a single face that is offset from a face of an existing body. The Offset Face menu has only one variable, the Offset distance. Positive offsets will create faces offset away from the normal direction of the existing face. Negative offset distances will create faces offset toward the center of the existing body.
Click one of the links below to view the dialog options or steps on how to use the function: