It is believed that the nanoparticle sized extender pigment particles, for example illustrated as ZnO, have an affinity for the surface of {HEAD ~ TiO2 particles} that aides in spacing {TAIL ~ the TiO2 particles} 
aides in spacing
It is believed that the nanoparticle sized extender pigment particles , for example illustrated as ZnO , have an affinity for the surface of { HEAD ~ TiO2 particles } that aides in spacing { TAIL ~ the TiO2 particles }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL