Iyo bigeze ku bijyanye n'umupira wamaguru, abakinnyi bakoresha birashobora kugira uruhare runini mubikorwa byabo. Kimwe muri ibyo bikoresho byingenzi ni inkoni y’umupira wamaguru, yagiye ihindagurika mu myaka yashize. Mu bikoresho bitandukanye, fibre ya karubone yagaragaye nkibyo byamamaye ku nkoni z’umukino wa ice kubera imitungo idasanzwe. Gusobanukirwa ibyiza byumupira wamaguru wa karubone fibre.