There are a large handful of variations of the word “dupioni”: douppioni, doppione, duponi, dupion … and probably others. I’m going to run with “dupioni” just because that’s what seems to be the most common. Whatever your preferred spelling, they all refer to a type of silk made from double cocoons. Many sources say that it’s silk from two or more cocoons that were spun too closely together, becoming entangled. This silk is weaker and rougher than silk from first-quality single cocoons — and irregular — which translates to the signature weftwise slubs in silk dupioni fabric. The texture is lovely, as is its characteristic dull sheen.
Silk Dupioni is a plain weave fabric that uses regular silk yarn for the warp and dupioni yarn for the weft (selvedge to selvedge or crosswise). Dupioni yarns are not strong enough to be used for the warp in weaving. Different colored yarns are often used for the warp and weft (same as shot cottons), yielding an iridescent effect.
The fabric is widely available and popular both for home decor and special occasion apparel, like wedding gowns. It has a crisp drape — unlike charmeuse and jersey, it is suitable for more tailored, fitted garments, and has almost zero stretch. Though it is a more affordable member of the silk family (starting around $12/yard), it unravels easily, the surface tends to pill, and seams tend to slip under stress. However, its crispness makes it wonderful for embellishment like beading and embroidery. It is widely available in a zillion colors.
I couldn’t see how side-by-side cocoons could yield anything but a tangled-up hunk of filament, so I asked Michael Cook of the fabulous all-things-silk website wormspit.com for an explanation. He said when the thread is reeled, it comes up as long, doubled strands with occasional slubs where the threads pull one another up. He also noted that true dupioni cocoons are single cocoons with two caterpillars inside, rather than the side-by-side cocoons. In practice, he added, other irregular, thin, or otherwise flawed cocoons are included in the stock. There’s a term in Japanese, Tsumugi, that refers to silk techniques using second or flawed cocoons.
The video below, in Japanese, shows artisans reeling dupioni cocoons, spinning thread, and weaving fabric. Midway through there is a good shot showing the difference between regular thread and the slubby dupioni thread.
It’s likely that silk dupioni is available in your local fabric shops, especially ones that sell special occasion or home decor fabrics. Here are some online sources:
The swatch in the images above was included with All About Silk: A Fabric Dictionary & Swatchbook (Fabric Reference Series, Volume 1) by Julie Parker, which also served as a general reference for this article and series.
and big thanks again to Michael Cook!