{HEAD ~ Subsequent layers} are spun onto the top surface of prior layers and exposed, and upon completion of the succession of layers {TAIL ~ each} defining corresponding levels of the desired structure, the layers are all developed at the same time leaving the three dimensional structure 
{ HEAD ~ Subsequent layers } are spun onto the top surface of prior layers and exposed , and upon completion of the succession of layers { TAIL ~ each } defining corresponding levels of the desired structure , the layers are all developed at the same time leaving the three dimensional structure
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH