pervious admitting of passage or entrance; "pervious soil"; "a metal pervious to heat"
impermeable preventing especially liquids to pass or diffuse through; "impermeable stone"; "an impermeable layer of scum"; "a coat impermeable to rain"
fast (of a photographic lens or emulsion) causing a shortening of exposure time; "a fast lens"
acid-fast not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)
colorfast having color that is resistant to fading or running
greaseproof resistant to penetration by grease or oil or wax; "greaseproof wrapping paper"
