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, rise 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 separate pieces of leather. This is generally the most affordable construction; its condition and the work needed determine whether a particular pair can be repaired.
• Dakkot: batim formed from one very thin piece of leather. The construction name describes how the boxes are made; the finished pair still needs to meet the halachic requirements for kosher tefillin.
• Gassot: batim formed from one thick piece of leather, the substantial construction used for gassot tefillin. The thicker leather generally offers greater durability and more scope for professional reshaping and refinishing, depending on its condition. Our Mehudar Gassot sets use this construction.

A first pair should be chosen with the same care for kashrus as any other pair. Our Basic Kosher tefillin sets combine leather batim, checked parshiyot, and Or-Elyon straps. The construction terms above describe the boxes rather than the beauty of the writing inside them. Chabad.org’s guide to tefillin construction explains the distinctions between peshutim, dakkot, and 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. Each box contains all four Torah passages, and a missing or extra letter, or a letter whose form is halachically invalid, makes the affected tefillah unfit for use. 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 arm tefillin and head tefillin are two distinct mitzvot, even though we ordinarily wear them together. That distinction matters when a sofer finds a problem in only one of them. The separate obligations and the four head compartments are explained in the mitzvot and structure of tefillin.

The parchment itself matters too. Tefillin are written on klaf, parchment prepared from the hide of a kosher animal; 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 manually by a Certified Sofer STaM, and reviewed by our in-house Certified Sofer STaM 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. Some less expensive straps use shpalt, a lower split layer of the hide. 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, the leather layer and whether it is processed by hand are separate details worth confirming when choosing a pair.

Who Makes Ours

We are a family business, and every set we sell contains parshiyot handwritten in Israel by a Certified Sofer STaM and is assembled from the components described above. Computer checking and manual examination, including review at our Los Angeles workshop, take place 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 prepared with the same care for kosher parchment and sacred lettering.