Speak unto the children of Israel, and bid them that they make them throughout their generations fringes in the corners of their garments, and that they put with the fringe of each corner a thread of blue. And it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of the LORD, and do them; and that ye go not about after your own heart and your own eyes, after which ye use to go astray (Bamidbar 15:38-39)
The Torah commands us to make tzitzit for ourselves – v’asu lahem tzitzis (Bamidbar 15:38). Citing this verse the Talmudic Sages explain that tzitzit strings must be made with intent ("lishmah"), i.e. when making the strings you must intend for them to be used for the mitzvah of tzitzit. Therefore according to halacha, when making tzitzit strings you must have the mitzvah of tzitzit in mind. You cannot simply buy or make strings and then call them tzitzit.
Herein lies the difference between the various levels of tzitzit production:
Machine-spun tzitzit (often referred to as "kaful shmoneh")
Handspun tzitzit ("avodat yad")
Niputz Lishmah tzitzit
Machine-spun tzitzit are made by machine, of course. The person operating the machine has "mitzvah intent" when he presses the buttons to activate the machine. According to the more lenient opinions, this is sufficient and the tzitzit are considered kosher. This is the type of tzitzit that comes standard on most tallit gadol and tallit katan products.
According to other opinions, the tzitzit must be spun by hand.
And finally, according to the most stringent opinion, the tzitzit strings must not only be spun by hand ("tevia"), but in fact must be made with mitzvah intent starting at an early stage in the production process, carding ("niputz"). These tzitzit strings are commonly referred to as niputz lishmah.
The main stages in the tzitzit production process are gozez (shearing), libun (bleaching), niputz (carding), tevia (spinning) and shezira (plying). According to the Shulchan Aruch the tevia must be done lishmah (i.e. the spinning must be done with mitzvah intent). The Rema notes that according to some opinions the niputz stage must also be done lishmah (carding with mitzvah intent), though he adds that the prevalent custom is to be lenient.
Note that all of the above only refers to the making of the tzitzit strings. Once you have kosher strings, according to all halachic opinions they must be tied on the tallit or tallit katan garment by hand; there is no such thing as "pre-tied" tzitzit that can then be attached.
Thin or Thick?
Whether to choose thin or thick tzitzit strings is essentially a question of aesthetics. Typically thin tzitzit are tied on a tallit katan, although some may prefer thick, which are less likely to break and may be a bit easier to tie. On a tallit gadol, thin tzitzit are generally standard. A high-end traditional wool tallit is often be sold with no tzitzit, and in that case thick tzitzit strings are more commonly used.
Ashkenazi or Sephardic?
The essential difference between Ashkenazi tzitzit and Sephardic tzitzit is the way in which they are tied. The actual tzitzit strings are the same. The only difference between "Ashkenazi tzitzit strings" and "Sephardic tzitzit strings" is the kashrut organization that supervises the production. In some cases even two different organizations use the exact same production supervisors.
The tzitzit strings we sell are under the supervision of Rabbi A.A. Wosner, Beit Yosef and the Eida Charedit Yerushalayim.
Tzitzit questions? Try our Tzitzit Wizard, or drop Ben a note and you can expect a swift reply – sometimes within minutes, usually within hours, always within one day (24/6).