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