Canvas is made from cotton. Cotton being a naturally occuring fiber has numerous enemies in the world of microbes. That means careful handling between uses is necessary to keep the canvas from rotting. Nylon and polyester being man-made products have no microbial enemies. Sun and wear may get them but not microbial rot.

: Ive been hearing talk about making a Kayak out of canvas, and was
: wondering what kind of canvas would i be using, and if there was
: anyone out there that might have some plan's that they could
: either share or direct me to a place or site where i could
: inquire about this.. Im looking to save money, but not degrade
: the structure of the kayak