Suitable sacrificial materials include polymers such as wax and epoxies, {HEAD ~ metals} such as aluminum, and {TAIL ~ glass} 
such as
Suitable sacrificial materials include polymers such as wax and epoxies , { HEAD ~ metals } such as aluminum , and { TAIL ~ glass }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL