Babylonian Shabbat Et A'B} Gm' Rav said that parchment is like Doxustus [what is Doxustus] They write on it a mezuzah, even parchment. They write on it a mezuzah, and so is the halakha, but tefillin are not written on the doxustus:
{Mishnah Shabbat 0:0-0} Matni' Ink to write two letters on it, strong enough to make one eye blue, pitch and sulfur to make a small hole in it, wax to put on the mouth of a small hole. Glue to put on the head of a clay vane to make the mouth of agoldsmith's furnace, R. Yehuda says to make a drop of bran to put on the mouth of a goldsmith's furnace, lime to seal a small finger in the daughters of R. Yehuda says to make everything, R. Nehemiah says to make earthenware as the seal of the scribes, the words of R. Akiva and the sages [say as the seal of the letters] dung and fine sand to make dung, a cob of cabbage