Pratimokshasutra of the Sarvastivadins 1.44

1.44

「若比丘，欲作新敷具，應用二分純黑羺羊毛、第三分白、第四分下。若比丘不用二分純黑羺羊毛、第三分白、第四分下作新敷具，尼薩耆波夜提。

"If a bhikṣu wishes to make a new rug, he should use two parts pure black goat's fleece, a third part white, and a fourth part of inferior [wool]. If a bhikṣu makes a new rug without using two parts pure black goat's fleece, a third part white, and a fourth part of inferior [wool], it is a niḥsargika-prāyaścittika.