cap: usually associated with "the torsion box effect," which occurs when the ski is flexing and causes the ski to twist. (its bad) However, cap cunstruction ranges significantly in qhality from bare minimum to high quality. some cap skis delam like no other, but some cap skis hold up better than sandwich due to sandwich's tendancy to get chips on the edges due to sandwich's 90* sidewalls. cap skis are usually lighter and cheaper.