How Tefillin Are Made

Shopping for tefillin (phylacteries) is confusing: prices range from a few hundred dollars to several thousand, often with no explanation of what changes between them. The difference is real, and it lives in three components. This guide explains each one, so you know exactly what you are paying for.

Every pair of tefillin has three parts: the batim (the black boxes), the parshiyot (the handwritten scrolls sealed inside them), and the retzuot (the black leather straps). Quality, and price, rises component by component.

The Batim (Boxes)

The batim are made of specially processed, stiffened leather. Halacha sets strict requirements: the leather must be processed lishmah (for the sake of the mitzvah) by a Jew, each box must be perfectly square, the arm box (shel yad) holds one compartment, and the head box (shel rosh) holds four, with the letter shin formed on both sides, including the rare four-headed shin on the left.

There are three main construction grades, from entry level to finest:

• Peshutim: batim assembled from several pieces of thin leather glued together, kosher by way of halachic leniencies. The most affordable construction, but it cannot be repaired once the seams give, and typically serves for only several years of daily use.
• Dakkot: a genuine single-hide construction, one thin piece of leather formed over a base. Lighter and more refined than glued batim, accepted by all opinions, and the construction we use on our Basic Kosher tefillin sets.
• Gassot: the finest construction, pressed from one thick piece of ox hide under enormous hydraulic pressure, then hardened naturally, typically for one to two years depending on the batim maker. Gassot are the only batim a professional can sand, re-square, and repaint, which is why a quality pair can last for generations and be passed down. All of our Mehudar Gassot sets are gassot.

The Parshiyot (Scrolls)

Inside the batim sit the parshiyot, the Torah passages handwritten on klaf (parchment) by a certified sofer STaM, a scribe trained specifically to write Sifrei Torah, tefillin, and mezuzahs. A complete set contains 1,594 letters, and a single malformed, missing, or extra letter renders the entire pair not kosher. The parshiyot are typically the largest share of a complete set's cost, and the writing quality, the evenness of the letters, the completeness of the tagin (crowns), and the level of hiddur is the main thing separating one price tier from the next.

The parchment itself matters too. Most tefillin and mezuzahs are written on klaf, the outer layer of the hide; you can read about klaf and the rarer gevil in our article on gevil and klaf. The exact letter forms follow a defined tradition, explained in our guide to STaM lettering styles.

How They Are Checked

Writing is only half the work. Our parshiyot are computer-checked letter by letter, examined by a magiah (a certified examiner), and reviewed by our in-house Torah scribe in Los Angeles before they ever reach a customer. Even with modern tools, a real mistake can slip through an unchecked pair, as we showed in our post on a mistake found in tefillin.

You can read more about what checking involves in our guide to mezuzah and tefillin checking.

The Retzuot (Straps)

The retzuot bind the batim to the arm and head, and they carry their own halachic requirements: leather from a kosher animal processed lishmah, a completely black outer surface, and a minimum width of 9 to 11 millimeters depending on custom. Quality varies more than most buyers realize. Budget sets use shpalt, split leather that tears and wears quickly. Our sets use or elyon, the strong top-grain layer of the hide, painted black on both sides, and our gassot sets are fitted with avodat yad retzuot, hand-processed from start to finish.

Because the straps are a real part of the mitzvah and not an accessory, upgrading from shpalt to or elyon to avodat yad is one of the clearest differences between a budget pair and a serious one.

Who Makes Ours

We are a family business, and every set we sell is handwritten in Israel by a certified sofer STaM, assembled from the components described above, and checked three ways before shipping. If you are choosing between traditions or scripts, see our kosher tefillin, or reach out; helping you get this right is what we do.

You can also compare the handwritten kosher mezuzah scrolls written on the same klaf by the same scribes.