If your windows are newer and coated with silver (LoE or LoE2) they block
most of the UV rays. keep us posted!--dave
wrote in message
oups.com...
I wondered about how much UV my windows blocked (assuming UV is what
matters).


toller wrote:
in the sunshine clearly darkened more than those in the artificial
light. The strip in the sunshine was not outside, but inside on a
windowsill. The strip left in the dark showed no appreciable
darkening
in any of the sections.

I hope you were careful to use a window that didn't block UV...