Machon Ot - Tefillin - The Batim

Types of Batim - Cowhide

"Gassot" are made from thick cowhide, tanned under great pressure, and form a perfect square. The entire Bayit from top to bottom, including the inner partitions of the Shel Rosh, is made from a single piece of leather. A well made pair of teffilin of cowhide will remain a perfect square, the color will not fade. This is the halachic preference.

Tefillin - Identifying Cowhide Batim

How to Identify Cowhide Batim

One way to identify cowhide Batim is through the distinctive sinew grooves. These can be seen when examining the underside of the Batim. They do not exist in Batim made of sheepskin.

How to Choose Cowhide Batim

It is important to examine the Batim before they are dyed to ascertain that there are no holes or depressions which would disqualify the tefillin. Likewise, there should be no holes filled in with glue. The tefillin should be perfectly square and the grooves of the Bayit Shel Rosh should reach the seam.

How Tefillin of Cowhide are Made

Tefillin Shel Yad as seen from above	Tefillin Shel Rosh as seen from above
stage 1		stage 1
stage 2		stage 2
Tefillin Shel Yad as seen from below	Tefillin Shel Rosh as seen from below
stage 1		stage 1
stage 2		stage 2