The properties of the polyvinylpyrrolidone (PVP) photoresist activated by DAS (4,4'-diazidostilbene-2,2'-disulfonic acid disodium salt) were studied for a period of one week while exposing the photoresist to different lighting conditions. The results from this study showed that white light caused the DAS in the photoresist to degrade and also caused the PVP and DAS to crosslink. The exposure of the photoresist to yellow light and no light caused minimal DAS degradation and crosslinking of the photoresist. Exposure to air caused the DAS degradation rate to increase and inhibited the crosslinking reaction between PVP and DAS. Finally, both unexposed and exposed DAS were determined to be crystalline, each with different structures. (C) 2003 Wiley Periodicals, Inc.