Headgear made of good French open fabric (6)
I believe the answer is:
bonnet
'headgear' is the definition.
(I know that Bonnet is a bonnet)
'good french open fabric' is the wordplay.
'good french' becomes 'bon' ('good' in French).
'open fabric' becomes 'net' (I've seen this in another clue).
'bon'+'net'='BONNET'
'made of' acts as a link.
(Other definitions for bonnet that I've seen before include "Headwear for a car?" , "Type of woman's hat" , "Baby's hat" , "Headgear -engine cover" , "Cover for head or engine" .)