▁ ▁The ▁setting ▁of ▁un mod ified ▁pl aster ▁starts ▁about ▁ 1 0 ▁minutes ▁after ▁mixing ▁and ▁is ▁complete ▁in ▁about ▁ 4 5 ▁minutes ; ▁however , ▁the ▁cast ▁is ▁not ▁fully ▁dry ▁for ▁ 7 2 ▁hours . ▁ ▁Now ad ays ▁band ages ▁of ▁synth etic ▁materials ▁are ▁often ▁used , ▁often ▁kn itted ▁fi berg lass ▁band ages ▁im pre gn ated ▁with ▁poly ure th ane , ▁sometimes ▁band ages ▁of ▁therm op last ic . ▁These ▁are ▁l ighter ▁and ▁dry ▁much ▁faster ▁than ▁pl aster ▁band ages . ▁However , ▁pl aster ▁can ▁be ▁more ▁easily ▁m ould ed ▁to ▁make ▁a ▁sn ug ▁and ▁therefore ▁more ▁comfortable ▁fit . ▁In ▁addition , ▁pl aster ▁is ▁much ▁sm o other ▁and ▁does ▁not ▁sn ag ▁cl othing ▁or ▁ab rade ▁the ▁skin . ▁ ▁Cast ▁types ▁ ▁Upper ▁extrem ity ▁Upper ▁extrem ity ▁cast s ▁enc ase ▁the ▁arm , ▁w rist , ▁or ▁hand . ▁A ▁long ▁arm ▁cast ▁enc ases ▁the ▁arm ▁from ▁the ▁hand ▁to ▁about ▁ 2   in ches ▁below ▁the ▁ar mp it , ▁leaving ▁fingers ▁and ▁thumb s ▁free . ▁A ▁short ▁arm ▁cast , ▁in ▁contrast , ▁stops ▁just ▁below ▁the ▁el bow . ▁Both ▁vari eties ▁may , ▁depending ▁on ▁the ▁injury ▁and ▁the ▁doctor ' s ▁decision , ▁include ▁one ▁or ▁more ▁fingers ▁or ▁the ▁thumb , ▁in ▁which ▁case ▁it ▁is ▁called ▁a ▁finger ▁sp ica ▁or ▁thumb ▁sp ica ▁cast . ▁ ▁Lower