We solve analytically for the perimeter-area generating functions for
two models of vesicles. While from the solution of the first model, st
aircase polygons, one can easily extract the asymptotic scaling behavi
or, the exact solution of the second, column-convex polygons, is diffi
cult to analyze. This leads us to apply a recently developed method fo
r deriving the scaling behavior indirectly, utilizing a set of nonline
ar differential equations. One result of this work is a nontrivial con
firmation of the scaling/universality hypothesis.