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Jiri Borsky · 23-09-2006, 08:40 PM posted to uk.rec.gardening

wrote:

I have a balcony constructed from cedarwood decking. When the decking

was originally laid, about 3 years ago, it had a wonderful lustrous
reddish-brown colour, which has gradually faded until now its usual
colour is a silver-grey. But the odd thing is, when it rains, the
water seems to bring up the original vibrant colour, which stays until
the wood dries again, when it goes back to grey. Does anyone have the

explanation for this phenomenon? Might it be possible to retain the
original colour even when the wood is dry - without using a stain?

Ken

The explanation: Water and other liquids conduct light in a different way
to air. When the wood (soil, fabric, etc) is wet, it reflects light
differently from when dry. Usually it appears darker, as more light rays
penetrate deeper via the liquid filling the spaces and get absorbed there.
When the liquid evaporates it is again replaced by air (with smaller
refraction coefficient) and the surface appears lighter.

To retain the darker "wet" appearance you would have to fill the pores
of dry wood with some non-evaporating substance, such as wax.

Jiri Borsky
http://www.borsky.com