One of standard whiteness? (5)
I believe the answer is:
sheet
This could be a double definition.
'one of standard' is the first definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'whiteness?' is the second definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
Can you help me to learn more?
(Other definitions for sheet that I've seen before include "Piece of paper; nautical rope" , "Large piece of fabric" , "Piece of paper or bedding" , "Page of postage stamps" , "newspaper" .)