Yesterday, Cory posted a vintage ad for boys' hats and accessories, which included a small selection of ties made from something called "Aralac". I didn't think much of it, until I noticed J. Brad Hicks' comment pointing out that Aralac was a synthetic wool made from cheese. Which was not a joke.
Seriously. It'll make more sense once you understand how the stuff was actually made.
Think about it this way: Wool (the actual kind, that comes from sheep) is a protein. So is casein, which is found in milk. Making Aralac is basically about getting the protein casein to behave like the protein wool. In 1937, Time magazine described how the process worked:
Having practically the same chemical composition as wool, it is made by mixing acid with skim milk. This extracts the casein, which looks like pot cheese. Evaporated to crystals, it is pulverized and dissolved into a molasses consistency, then forced through spinnerets like macaroni, passed through a hardening chemical bath, cut into fibres of any desired length. From 100 pounds of skim milk come 3.7 pounds of casein which converts to the same weight of lanital. [Aralac was also called Lanital.]
Casein isn't cheese, as J. Brad Hicks described it. Instead, it's the stuff that makes cheese happen. If milk is the liquid and cheese the solid, casein is the stuff that facilitates the transition — the casein in milk clumps together and solidifies into cheese.
So, in a way, Aralac really was cloth made from cheese. During World War II, when wool was scarce, it made a lot of sense to buy Aralac — which was significantly cheaper and easier to get a hold of.
Why don't we wear Aralac today? Couple reasons. First off, it wasn't a particularly strong fiber. According the Powerhouse Museum in Sydney, Australia, Aralac fibers were only about 10% as strong as natural wool, so the stuff was usually mixed in a wool-Aralac blend to improve durability. And, despite assurances to the contrary in that 1937 Time story I quoted above, Smithsonian says Aralac was a royal pain to successfully dye.
It's also worth noting that Aralac isn't totally gone. In fact, there's a German company trying to market QMilch — a fabric made from milk that isn't deemed high enough quality to be sold as food. It's apparently more like silk than wool.
• The Time magazine story is behind a paywall, but you can read a 1944 Life magazine piece on Aralac for free at Google Books.
• Smithsonian on H. Irving Crane, inventor of Aralac
• The Powerhouse Museum on Aralac and other synthetic fibers
• Read a brochure on Aralac from the 1950s
Special thanks to J. Brad Hicks and the Knitty Professors blog
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.