When printed casting tape was first introduced by in the early 1990's, it was intended to be used as a finishing tape to be applied over a typical fiberglass cast. It was marketed as Flashcast and was not intended to be used for constructing a complete cast.

The printed polyester tapes were not as thick as regular fiberglass tape and were somewhat transparent so different color effects could be obtained by placing the printed tape over a light colored base tape such as yellow, pink, or any of the fluorescent colors.Several years later, a more substantial solid-color polyester casting tape was marketed for constructing complete casts. The primary difference between the fiberglass and polyester tape was that a knitted polyester fabric had been substituted for the fiberglass fabric substrate. The result was a tape that looked and felt much like standard fiberglass tape but was lighter in weight and more flexible.

There were several published studies that compared the performance of polyester and fiberglass tapes.The results indicated that the differences between the performance of the two different tapes were small. An equal number of material breakdowns and delaminations were identified in both polyester and fiberglass casts.

A review of patient comments revealed that several of the patients who were fitted with polyester casts had previous experiences with fiberglass casts. Their comments reflected on the feeling of instability or lack of strength in their polyester cast and the need for strengthening or reinforcement. They preferred the hardness of the fiber cast to the less rigid polyester cast.

You might want to consider applying a regular fiberglass cast and then finish it with the polyester tape. You'll have the best of both worlds.