Perhaps Klein bottle volume with positive sign? (4)
I believe the answer is:
yves
'perhaps klein' is the definition.
(Yves Klein was an artist)
'bottle volume with positive sign?' is the wordplay.
I cannot quite understand how this works, but
'volume' could be 'v' (abbreviation for volume in book titles) and 'v' is present in the answer.
'positive' could be 'yes' and 'yes' is found within the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for yves that I've seen before include "-- Saint-Laurent, French fashion designer" , "-- Saint-Laurent, couturier" , "French man" , "-- Montand (French actor)" , ". . . . Saint Laurent, fashion designer" .)