Blots, blemishes (6)
I believe the answer is:
stains
I believe this clue is a double definition.
'blots' is the first definition.
(I know this)
'blemishes' is the second definition.
(stain is a kind of blemish)
(Other definitions for stains that I've seen before include "Discolorations or dirt marks" , "Dirty marks" , "Discolours or dyes wood" , "Discolorations or blemishes" , "Discolourations on satins" .)