A vision system examines droplets monitoring quality and a feedback signal to vary {TAIL ~ the material} in {HEAD ~ each droplet} 
A vision system examines droplets monitoring quality and a feedback signal to vary { TAIL ~ the material } in { HEAD ~ each droplet }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD