UV filters, provided they are attached properly (sometimes, esp. when changing bulbs, the shield may not be set to completly cover the bulb) provide good protection against UV induced light damage. Research, primarily from the Canadian Conservation Institute, suggests that the filtering capacity lasts for at least 10 years. Jack C. Thompson Thompson Conservation Lab Portland, OR [log in to unmask] On Tue, 3 Jan 1995, Alex Barker wrote: > Does anyone have experience with the use-life (and general usefulness) of > fluorescent light UV filters? How long do they remain effective? > > Alex Barker >