Developable mechanisms offer the ability to deploy to perform tasks then return to a hidden position along or interior to a predetermined developable surface. It is often advantageous for these mechanisms to not penetrate the surface along which they conform. This paper presents the limits of extramobile and intramobile motion (motion exterior to and interior to a developable surface). Three conditions are identified that determine a limit of extramobile and intramobile behavior. It is shown that the more difficult of these conditions to predict is never reached prior to the more simple cases. This is demonstrated for all possible Grashof and non-Grashof mechanisms, excluding change-point mechanisms.