The Torah forbids the wearing of a garment made of a wool and linen blend, known as a shatnez, but it does not explain why Jews should follow this rule. And most Jews do not. We choose which ancient values and traditions to uphold. Perhaps we will never eat pork (it feels wrong), but we will enjoy shrimp fried rice from time to time. We probably don’t think about whether our clothes are kosher or not. When I learned about shatnez, I was intrigued by the fiber-focused decree. The top search results show Orthodox Jews (“shatnez inspectors”) examining fabrics under a microscope. I imagine they are closely examining the scaly texture of wool’s hair and the bamboo-like shape of linen fibers. The two must not mix. Why? Because it is written. But surely there must be other things we should consider.
I discovered Shatnez through a Wikipedia article while doing a research project on Jewish textile traditions for an adult secular bar mitzvah at the Morris Winczewski Centre in Toronto. As a textile conservator by trade and a triple-team knitter/quilter/weaver outside of work, I am often challenged with choosing the right material for a project. Wool and linen are both different but wonderful in their own right. So when I found out that mixing the two is illegal (or at least non-Jewish)?! I was a mixture of amused and disappointed. This unreasonable law stuck in my mind as I finished my bar mitzvah project, embroidering a challah cover and quilting a matzah bag out of cotton and linen. Perhaps because I knew it was forbidden, I was eager to try mixing wool. But with a ritual textile like this, I felt bound by convention. Surely I must understand the rules before I break them?
I am of Reform Jewish and atheist descent and have decided to limit my Jewish education to the Hanukkah special of Rugrats, so I am far from an educated Torah scholar. However, I am a textile scholar and manufacturer who has been involved in issues of preservation and sustainability in various ways. Anyone who knows me has heard me preach about checking the material labels on clothing and choosing natural fibers like cotton and wool over synthetic fibers like polyester and acrylic. It is rare to come across modern clothing made from wool and linen blends (though I recently got an ad for a merino wool and linen blend t-shirt…is shirtnez making a comeback?). In general, both fibers are being phased out of large-scale use in the fashion industry and replaced by cheaper synthetic materials. Wool and linen are mostly found in expensive designer clothing and brands that specialize in sustainable fashion.
Clothes made from natural fibers are easier to repair and last longer, while synthetics tend to pill, yellow, overstretch, and become littered with white specks of broken rubber. Natural fibers resist odors and require less frequent washing. Synthetic fibers are useful for many applications (no offense to the nylons that hold your socks up), but they are extremely harmful to our rapidly deteriorating environment and sometimes even to our health. Shirtnez was invented before synthetic materials polluted the world, but it asks us to think carefully about what we wear and choose what we don’t. According to Jewish law, synthetic fibers are not kosher. But are they kosher according to our values?
The law against shirts has been interpreted as stipulating that it applies only to sheep’s wool, not to goat hair such as mohair or cashmere, or to the hair of other animals. It also applies only to linen, which comes from the flax plant, and not to other plant fibers such as cotton or flax. A chapter in Deuteronomy specifically states that wool and linen may not be worn together. This rule is not widely believed, since it appears in the same chapter as a passage that forbids women from wearing “men’s things” and vice versa. However, a chapter in Leviticus more generally forbids “the mixing of two kinds of material in garments.” The reasons for the seemingly arbitrary prohibition against mixing wool and linen have been theorized but are unknown.
From a practical standpoint, blends may be discouraged because wool and linen react differently to washing, preventing uneven shrinkage and easing the once arduous task of laundry. If so, then shouldn’t fragile fabrics blended with cheap polyester, spandex, nylon and rubber also be banned, especially given the harmful microplastics released with every wash?
The religious explanation is that linen and wool were used together in the robes of the kohanim (priests) and pagan priests, and therefore should only be worn by those who serve God. Is shirtnez so beautiful that it is reserved only for God? Is it forbidden because it is sacred? It is included in a list of forbidden combinations, including women wearing men’s clothing, men wearing women’s clothing, and linen and wool.
Sometimes called Lindsey Woolsey (a name I give to drag queens who advocate for shirtnez), the wool and linen blend can symbolize a rejection of binary or sacred cross-dressing. Wearing shirtnez can be a sacred transgression, akin to wearing gender-affirming clothing, in violation of ancient rules about non-conforming bodies for queer and transgender Jews.
We live in a different world than the one that defined shirtnez, and I propose a contemporary interpretation of the shirtnez that invites us to think about the clothing Jews wear, what it is made of, and who made it.
Wool and linen blends offer a natural delicacy in a fashion industry dominated by polycotton and stretch denim. While many fast fashion brands “greenwash” their products by making garments from recycled synthetic materials, it is true that blended fabrics are difficult, and sometimes impossible, to recycle. Historically, cotton and linen rags were stored, reused, and eventually given to shmat collectors, who could sell the rags in the paper industry. Other fibers may also be reused, and historical Torah ark curtains were often made from repurposed scraps of fine fabrics such as velvet and brocade.
Like many cultures that have endured hardship, Jews have a historic tradition of thrift and the appreciation of scraps. Synthetic fabrics, made primarily from petroleum-based plastics, are purposefully short-lived and do not degrade over time. The chances of your overstretched jeggings being reused or recycled are slim. When establishing your personal fashion discipline, you need to consider not only the origin of your clothing but also its end of life.
Is fast fashion a modern-day shirtnez? The textile and garment industry has a significant Jewish history that resulted in the founding of labor unions that defended the rights of garment factory workers. As major fashion companies move production to areas where labor is more exploitative, it’s easy to take for granted the contributions of our ancestors to labor rights in the communities where we live, yet the workers who make our clothes continue to struggle for fair wages, hours, and workplace safety.
My hope is that a modern interpretation of Shirtnez will inspire a renewed interest in the materials around us and a greater appreciation for the materials we would not choose. We don’t have to take every outdated Jewish law literally, but rather than discarding some of it entirely, we can adapt some to better suit us.
