Mechanical and order rigidity of nematic elastomers

We calculate the ratio of moduli for extension parallel and perpendicular to the director of nematic elastomers. Elastomers in practice are not ideal nematics with a jump from a finite to zero-order parameter with increasing temperature. Some classes behave as if under effective external fields. These are really internal in origin and leave the system subcritical (still with jumps) or supercritical. We give expressions for general non-ideality, and memory of formation conditions; along with its translation into values of the fields''. For the case of supercritical fields, we find that the modulus ratio deviates more from unity, in accord with experiment, than in the subcritical case.