8 6 0 ▁was ▁that ▁of ▁making ▁the ▁dress ing ▁resist ant ▁to ▁water ▁by ▁painting ▁the ▁d ried ▁pl aster ▁of ▁Paris ▁with ▁a ▁mixture ▁of ▁sh ella c ▁dissol ved ▁in ▁alco hol . ▁The ▁first ▁commercial ▁band ages ▁were ▁not ▁produced ▁until ▁ 1 9 3 1 ▁in ▁Germany , ▁and ▁were ▁called ▁Cell ona . ▁Before ▁that ▁the ▁band ages ▁were ▁made ▁by ▁hand ▁at ▁the ▁hosp it als . ▁ ▁As ▁a ▁pl aster ▁cast ▁is ▁applied , ▁it ▁exp ands ▁by ▁approximately ▁ ½ ▁%. ▁The ▁less ▁water ▁is ▁used , ▁the ▁more ▁linear ▁expansion ▁occurs . ▁ ▁Pot ass ium ▁sul f ate ▁can ▁be ▁used ▁as ▁an ▁acceler ator ▁and ▁sod ium ▁bor ate ▁as ▁a ▁ret ard er ▁to ▁control ▁setting ▁time . ▁ ▁See ▁also ▁Bud dy ▁wrapping ▁H . ▁Win nett ▁Or r , ▁US ▁Army ▁sur geon ▁who ▁developed ▁orth op edic ▁pl aster ▁cast s ▁Anne ▁A ches on , ▁British - I r ish ▁sculpt or ▁who , ▁together ▁with ▁El in or ▁Hall é , ▁invent ed ▁and ▁developed ▁orth op edic ▁pl aster ▁cast s ▁Orth ot ics ▁D ental ▁bra ces ▁K end rick ▁Ext ric ation ▁Device ▁long ▁sp ine ▁board ▁ ▁H alo ▁( med ic ine ) ▁▁ ▁C erv ical ▁col lar ▁Back ▁bra ce ▁ ▁References ▁ ▁External ▁links ▁▁ ▁Pl aster ▁Cast s ▁& ▁Sam ' s ▁injury ▁at ▁The ▁Period ic ▁Table ▁of ▁Videos ▁( Univers ity ▁of ▁Not