[Fictionary] Easy to be Nard?

[eLLioTT morEton]

On Mon, 25 Nov 2013, fictioneric at inbox.com wrote:

>> eLLioTT morEton: Oooh! Nice. Why do things become darker when moistened? I 
>> asked that of Eric once (about paper towels), and he had a convincing 
>> explanation, which I won't spoil until everyone's had a chance to discuss 
>> it.
>
> I *did*?  Someone will have to tell me it.

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If I remember correctly, the hypothesis was that wetting the paper towel 
didn't change the total amount of light reflected from it; instead, it 
made the surface smoother by flattening down the fibers, so that from one 
direction it was shiny and from all the others it was dark.

Regards,
em