At one time, all awnings were made of cotton canvas fabric. While canvas is an environmentally friendly option, it does not stand up to the elements as well as synthetic fabric. Canvas rots in humid conditions and is susceptible to damage from sunlight. It also requires sealing with waterproofing products on a regular basis. Other drawbacks include fading over time and the tendency of dirt to gather in small gaps in the fabric.
A major problem associated with canvas is its susceptibility to fungus and mold when damp. Treating with a sealant does not always deter the growth of microorganisms. Canvas awnings are generally less expensive than awnings made of other materials, but due to their drawbacks have largely given way to awnings made of synthetic fabrics.