An economical method is disclosed for modifying the physical characteristics of a nonwoven fibrous web which involves passing the web between at least one pair of interengaged rolls to incrementally stretch the web, and then withdrawing the incrementally stretched web from between the rolls under tension. A web modified according to the disclosed method has advantageous elongation, extensibility and strength properties, as well as other desirable characteristics. In another aspect, a method is disclosed for forming a composite material by combining a modified nonwoven web with a polymeric film, or an elastic member, which may be liquid impervious yet breathable. In yet other aspect, a method is disclosed for forming a composite material by combining a modified web with a polymeric film which is rendered liquid-impervious yet breathable while the method is performed. The modified nonwoven webs and composite materials made according to the disclosed methods may be advantageously employed in absorbent articles such as disposable diapers.