Care and Maintenance of Tefillin Straps

2 Adar I 5771
February 6, 2011

tefillin-straps1Tefillin straps are the number one pasul or point of invalidation found in tefillin when tefillin are checked. Unfortunately most of us do not realize that the straps need to be examined regularly, in fact much more often than the scrolls.

There are two conditions on the straps which must be checked. The straps must maintain a minimum width and must be black on the outer side.

There are various opinions as to what is the minimum width of the straps. One should always check with his posek (rabbinical authority to determine which measurement is for acceptable for him. Ideally they should be at least 11 mm wide. Standard new straps on average are 14 to 15 mm wide so that when they thin out do to stretching they will retain the minimum requirement – However, they can and do thin out over a time as well as they can tear especially in the area of the knots and where they are wrapped around both the arm and the plastic covers.     

The other major issue is that the blackness of the straps. The straps having to be totally black on the outer side is a “Halacha Moshe m’Sinai” This is not a minhag or a custom. It is not a segula. It is a requirement with which if not met invalidates the entire mitzvah of tefillin shel yad or shel rosh.

The blackness of straps is determined only when being worn. Cracks and crevasses which can only be seen when the straps are bent and are clearly not black and do occur in both standard straps as well as the double sided black straps. These cracks can invalidate the straps.
The easiest way to examine your straps is to look at them and determine if they are really black on the top and if they are wide enough.  If they do not look totally black then one has two options – the first is to paint them with “kosher tefillin paint” the other is to replace them.

The most common cause of cracking paint or thinning is caused by wrapping the tefillin straps very tight around the covers, when one puts them away. The leather and the paint do not have the same elasticity and when stretched and under press the result will be that the paint will crack and sometimes peel. You can easily check if you are wrapping your straps too tight by looking at the bottom side of the straps at the beginning wraps against the cover. If the bottom of the strap shows any sign of indentation into the leather then you are winding it too tight. The looser the strap is wrapped around the cover the longer it will last. Remember stress free straps are the beginning to a stress free day.

To contact Rabbi Moshe Flumenbaum directly, one may email

Comments are closed.