“Partially thickened” means that {HEAD ~ the coating} is in a state between the two forms in which retains {TAIL ~ a measure} of malleability 
retains
“ Partially thickened ” means that { HEAD ~ the coating } is in a state between the two forms in which retains { TAIL ~ a measure } of malleability
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH