What Is the Difference Between “Thin Animal” Tefillin and “Thick Animal” Tefillin?

What is the difference between “Thin Animal” tefillin and “Thick Animal” tefillin? Did you know that in the past, all Jews used tefillin made from the skin of sheep and goats? Over time, new methods developed and they began using the skin of cows and bulls, which led to a significant improvement in the beauty and strength of the tefillin. Today, tefillin made from “thin animal” leather are considered merely kosher, while tefillin made from “thick animal” leather are considered mehudar (enhanced kosher). And what is the letter “Shin” on the tefillin? Discover the fascinating differences between the various types of tefillin and the halachic significance of each!

The difference between “thin leather” tefillin and “thick leather” tefillin

Until a few decades ago, all Jews used tefillin with the batim made from “thin leather.” That is, leather from sheep and goats, and since thin leather is thin, it was not possible to process it to a sufficiently beautiful and durable state. A few decades ago, they began using “thick leather,” which is leather from a cow or ox.

Even nowadays, one can find batim made from thin leather, but their level of kashrut is lower, and they are not of the same beauty and strength. Usually, tefillin from thin leather are considered only “kosher,” whereas only those made from thick leather are considered “mehudar” (exquisitely made).

What is the letter Shin on the tefillin?

Regarding the prominent letter “Shin” on the head tefillin – it is a law given to Moses at Sinai and contains great hints and secrets explained in the words of the Sages and the holy Zohar. It is emphasized by handcrafting and not by machine, which is a complex task. The entire difference between Ashkenazim and Sephardim in the tefillin batim is expressed only in the shape of the Shin on the head tefillin. Aside from the Shin, there is no difference in the form of the tefillin or in the process of making them.

What is a machine square, a foot square, a hand square? And which is the most exquisite?

When squaring the upper part of the tefillin, it must be done for the sanctity of the tefillin. There are several levels of mehudarut (excellence):

Machine square – The squaring of the bayit is done by an electric machine, and the operator says during its operation “for the sanctity of the tefillin.” Many poskim (Jewish legal decisors) have approved machine square.

Foot square – Making the tefillin square by a machine operated by a person’s foot pedaling, which is done for the sanctity of the tefillin – this is a more meticulous level than the “machine square.”

Hand square – where the person operates the machines by hand, and they work only by his own force; this is more meticulous than the above foot square, and because it is difficult, these sets are very expensive.