Imaam Shaafi‘ee (rahimahullah) narrates:

I was an orphan in the care of my mother, and my mother did not have anything which she could give to my Ustaad. However, my Ustaad was happy that when he would leave the class, I would see to the students in his absence. After I completed memorizing the Qur’aan Majeed, I entered the Musjid and began to sit with the ‘Ulamaa, memorizing the Ahaadith of Rasulullah (sallallahu ‘alaihi wasallam) and various masaa’il of Deen. Our home, in Makkah Mukarramah, was situated in the valley of the Mountain of Khaif. I would find bones that were clean and clear and on which I was able to write Ahaadith and masaa’il of Deen (as I could not afford paper to write on). We had an old jar in our home. Whenever I had written on the entire surface of the bone and there was no other space left to write, I would place it in the jar.

(Hilyatul Awliyaa vol. 9 pg. 82)