If we want to make the brush even stronger and more resilient, we should use pig bristles for the first tier, rabbit whiskers for the second tier, ox-ear hairs for the fourth and fifth tiers and fox hairs for the outer tier. The composition of these tiers determines the characteristics of the writing brush.
這件事情使李志仁從中悟出制筆的真精神，乃在「尖齊圓健」技術之外，也要懂得依照寫字者的性情、習慣與運筆方式來製造不同筆性的筆。