▁top . ▁The ▁label ▁can ▁be ▁applied ▁to ▁any ▁object ▁as ▁normal , ▁the ▁top ▁layer ▁can ▁be ▁a ▁remov able ▁label ▁that ▁can ▁be ▁applied ▁elsewhere , ▁which ▁may ▁change ▁the ▁message ▁or ▁mark ing ▁on ▁the ▁remaining ▁label ▁under ne ath . ▁O ften ▁used ▁on ▁Express ▁mail ▁en velop es . ▁Other ▁applications ▁include ▁price ▁change ▁labels ▁where ▁when ▁being ▁sc anned ▁at ▁the ▁till , ▁the ▁till ▁assistant ▁can ▁pe el ▁back ▁the ▁price - redu ction ▁label ▁and ▁scan ▁the ▁original ▁bar code ▁en abling ▁stock ▁flow ▁management . ▁These ▁labels ▁are ▁also ▁seen ▁on ▁magazine ▁subscription ▁renew als , ▁allowing ▁customers ▁to ▁re - subscribe ▁to ▁the ▁magazine ▁with ▁an ▁easy ▁pe el ▁and ▁stick ▁label ▁sent ▁back . ▁Also , ▁as ▁the ▁retained ▁label ▁is ▁ad hes ive ▁free ▁it ▁prevents ▁customers ▁from ▁re - app lying ▁the ▁che aper ▁pr iced ▁labels ▁to ▁prem ium ▁products . ▁ ▁Sm art ▁labels ▁have ▁R F ID ▁ch ips ▁embedded ▁under ▁the ▁label ▁stock . ▁Block out ▁labels ▁are ▁not ▁see - through ▁at ▁all , ▁conce aling ▁what ▁lies ▁under ne ath ▁with ▁a ▁strong ▁gray ▁ad hes ive . ▁Radio active ▁labels . ▁The ▁use ▁of ▁radio active ▁is ot op es ▁of ▁chemical ▁elements , ▁such ▁as ▁carbon - 1 4 , ▁to ▁allow ▁the ▁in ▁v ivo ▁tracking ▁of ▁chemical ▁comp ounds . ▁Las er ▁or ▁printer ▁labels ▁are ▁generally ▁die ▁cut ▁on ▁ 8 . 5 " ▁x ▁ 1 1 "