Study including exaggerated material (6)
I believe the answer is:
cotton
'material' is the definition.
(cotton is a kind of material)
'study including exaggerated' is the wordplay.
'study' becomes 'con' (I've seen this before).
'including' indicates putting letters inside.
'exaggerated' becomes 'ott' (short for 'over the top' - informal British).
'con' enclosing 'ott' is 'COTTON'.
(Other definitions for cotton that I've seen before include "Natural cloth" , "Plant fibre for fabrics" , "Old golfer" , "Soft fabric and fluffy wool (6" , "Substance like fine wool" .)