《太平广记·卷二百零八·书三》
将头浸入墨汁中用头书写，世上人称他为张颠酒醒后看见自己用头写的字，认为它神异而不可重新得到。
以头揾水墨中而书之，天下呼为张颠。醒后自视，以为神异，不可复得。
He would dip his head in ink and use it to write; people called him Zhang Dian (the Crazy Zhang). When he sobered up and saw the characters he had written with his head, he thought them miraculous and irreplaceable.