The actual covering is fuel proof. The trouble lies in the fact that it doesn't adhere to the balsa as well as other plastic coverings, leaving the opportunity for edges to lift allowing fuel underneath. If applied correctly with all seams facing against the airflow, fuel soaking will not be an issue. It is similiar to econokote and is applied at a lower temperature. It is suprisingly easy to work around corners and curves. The only downfall I can see, is that it is noticably thinner than others and will tear if you pull too hard when applying.