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