The present topic discusses the shape control of gossamer apertures. Once the aperture is deployed on orbit, final shape refinement has to be done to achieve the desired surface. This shape refinement could be achieved through active seams incorporating active elements like shape memory alloys and piezoelectric polymers like PVDF. Numerical simulation of the shape refinement of the gores of the aperture through active seam is reported. Experimental investigation of extensional PVDF actuators is presented. The theoretical extension of PVDF actuators is compared with the experimental values and the effect of seam adhesive is discussed. A simple prototype of an active seam is also presented.