Are we forgetting that light intensity is also harmful to sensitive materials, such as paper and fabric? Not only do you have to protect your collection from the damaging effects of ultraviolet radiation, but lux should be carefully monitored so that fading and embrittlement do not occur. While we may be able to mitigate UV damage with filters and sleeves, a print or watercolour (or banknote) will still fade if the well filtered light is too intense! As my professors used to tell us: Light damage is cumulative and irreversible. The Canadian Conservation Institute publishes notes and technical bulletins which outline collections care and preservation, such as proper lighting conditions. A light damage slide rule is available for purchase, which will tell you how much damage is being done to your artifacts from both UV radiation and lux. They can be contacted on the web at: http://www.pch.gc.ca/cci-icc/ The slide rule is listed under Products and Publications - S7E Light Damage Slide Rule - $20.00 A basic care-of-collections tool to which museum staff may refer to determine the intensity and duration of illumination that will best preserve the colour in artifacts for as long as possible. Slide rule and instruction booklet. Alex Avdichuk City of Toronto [log in to unmask] ______________________________________________________________________ How about using fluorescent tubes with UV sleeves? Its low heat, low cost, bright white light and with the UV sleeves, there should be no harm done. Just remember that the UV sleeves are essential. Mike Highfield >Could anyone comment on the use of halogen lights in a display case for >bank notes. Will this cause problems? What are the alternatives? Thanks > >V. Manalo We recently purchased TL 70 series fluorescent lamps (bulbs and tubes) for our museums and will be used in all of our exhibit spaces. I asked the manufacturer, Philips Lighting, what the UV output of these bulbs are and they answered "The UV wavelength is 400-700 nanometers which is visible light." The problem is that the museum literature I have on lighting refers to "microWatts per lumen" or mW/l. Does anyone know how to calcuate the nanometers into mW/l so I can really understand how much UV is being emitted by these new bulbs? I assume that I need to put a UV filter over each bulb. Thanks for any help! Mary Ames Sheret Curator of Collections/Exhibits Southern Oregon Historical Society