Icyuma kibonye ni ubutaka busabwa kugirango habeho ubunini bumwe. Nyuma yo gusudira cyangwa gucumura ibyuma, hazaba hari ingese nizindi nenge kuri substrate, bigira ingaruka kumiterere. Kuringaniza mbere yo gushushanya bizamura cyane isura nziza kandi byongere ibicuruzwa birushanwe. Icyuma cya Donglai gifite urusyo runini rusya ruzengurutse, rugera kuri mm 2200. Kuringaniza ibyuma bigera kuri mm 800 nabyo bikorerwa kumashini ikora neza.