Empirical evaluations closely simulating actual use conditions were employed to compare critical property levels of commonly used muslin (140-thread) and nonwoven sterile-wraps. Critical properties and experimental methods used to measure these properties are: (a) ease of steam penetration determined by time-temperature measurements in large, double-wrapped packs subjected to steam sterilization, (b) bacterial barrierness measured by microbiological assay of initially sterile double- and single-wrapped packs contents after pack storage in hospitals, (c) compatibility with ethylene oxide sterilization measured by inactivation of spore strips and by quantities of ethylene oxide residuals after aeration of packs and (d) generation of lint by counting particles generated by flexing wrap materials. It was concluded that the nonwoven steril-wrap was superior in ease of steam penetration, bacterial barrierness, and linting. No differnece was detected between materials in ethylene oxide sterilization.