The easy answer is "yes." But life is usually not that easy. Kevlar or graphite of the same strength would be lighter weight cloth, but it may also be thinner. The overall structural strength may be as good or better, but simple puncture strength may not be as good. Abrasion resistance will also be different, probably not as good. With a little bit heavier layup than strictly needed to match the overall strength of the fiberglass, you will gain back some of what you lost in other areas.

> I have decided, for sure now, to paint from the sheer line down on my
> Guillemot. Since I have not yet glassed the hull, I now have the option of
> using Kevlar or a carbon/kevlar cloth. If I do use kevlar or a
> carbon/kevlar cloth can I use a lighter weight cloth and still maintain
> the same structural integrity while saving some weight?