a) a plurality of polymeric, elastomeric microspheres wherein {HEAD ~ the microspheres} comprise {TAIL ~ the reaction product} of 
a ) a plurality of polymeric , elastomeric microspheres wherein { HEAD ~ the microspheres } comprise { TAIL ~ the reaction product } of
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH