Mulberry Silk vs Tussah Silk: Which Filling Belongs in Your Duvet?

If you are shopping for a silk comforter, you will quickly meet two names: mulberry silk and tussah silk. Both are real silk. Both make excellent duvets. But they come from different silkworms, feel different, and suit different sleepers. Here is how to tell them apart, and how to choose the filling inside your next comforter.

Two silkworms, two silks

Mulberry silk comes from the Bombyx mori silkworm, raised indoors and fed exclusively on mulberry leaves. Because the worms live in a controlled environment, their fibers are long, uniform, and naturally white. The best mulberry silk is graded 6A, the top grade for fineness and consistency.

Tussah silk (also called tussah, or wild silk) comes from tussah moths that live outdoors, feeding on oak and other trees. Their fibers are shorter, slightly coarser, and naturally golden-tan in color. Tussah is sometimes called “wild silk” because the moths are not domesticated the way Bombyx mori are.

Neither is “fake silk.” The difference is the animal, the diet, and the fiber it produces.

One more split: double cocoon vs single cocoon mulberry

Not all mulberry silk is the same. A single cocoon holds one silkworm; a double cocoon holds two, spinning their fibers together. That one difference changes the fiber: double-cocoon silk is thicker, stronger, and longer-lasting, while single-cocoon silk is finer and softer against the skin.

For a comforter filling, this is why double-cocoon mulberry is the premium choice: it is the strongest and warmest of the three, and it holds up the longest. Single-cocoon mulberry is the softest, the best pick when the fabric sits right against your skin. Tussah stays the value pick: just as warm as double-cocoon mulberry, at the lowest price, with a slightly firmer feel.

How they compare in a comforter

• Softness. Mulberry silk is the softer of the two. Its long, fine fibers lie smooth and drape like liquid. Tussah has a slightly firmer, more textured hand-feel. If you love a soft, weightless drape, mulberry wins. If you like a duvet with a little more body and structure, tussah holds its own.
• Fiber length. This matters more than most people realize. Mulberry fibers are long and uniform, so a mulberry filling stays evenly spread, resists clumping, and keeps its loft for years. Tussah fibers are shorter, so tussah fillings rely more on the comforter's internal quilting to stay in place.
• Warmth and breathability. Both are excellent temperature regulators. Silk fibers are hollow and naturally breathable, so a silk comforter keeps you warm in winter without overheating in summer. In practice, mulberry feels a touch lighter for the same warmth, which is why it is the usual choice for summer-weight comforters.
• Color. Mulberry silk is naturally ivory-white. Tussah is naturally golden-beige. Under a white or light-colored cover, a tussah filling can give the duvet a faint warm tint. Some people love the natural look; others prefer the clean white of mulberry.
• Price. Mulberry silk costs more to produce, and that shows up in the price. In our own comforter listing, the mulberry version runs a modest premium over the identical tussah version, size for size. Tussah is the better value if budget matters and you still want a genuine silk filling.
• Care. Both need the same gentle treatment: do not wash the silk filling. Choose a comforter with a detachable, machine-washable cover, and wash only the cover. Air the filling out occasionally, and store it in a cool, dry place away from direct sunlight.

How to choose the silk inside a silk comforter

1. 100% silk, or a blend? The label should say 100% silk filling. Blends with polyester or cotton cost less, but they give up much of what makes silk special: breathability, moisture-wicking, and that light, even warmth.
2. Long-strand or short fiber? Look for “long-strand” or “long fiber” silk. Long strands stay put and resist clumping and cold spots. Short or chopped silk fiber mats down faster and shifts inside the cover. Our comforters use double extra-long-strand filling for exactly this reason.
3. Fill weight, matched to the season. For a summer comforter, lighter is right: roughly 0.55 kg for a Twin, 0.65 kg for a Full, 0.75 kg for a Queen, 0.9 kg for a King, and 1 kg for a California King. Heavier is not automatically better. Silk regulates temperature on its own, so an overfilled summer duvet just adds weight you don't need.
4. Double cocoon, single cocoon, or tussah? Choose double-cocoon mulberry for the strongest, warmest, longest-lasting duvet filling; single-cocoon mulberry for the softest feel; tussah for genuine silk at the lowest price.
5. The cover matters too. A cotton cover, especially a cotton jacquard, breathes well and stands up to washing. A detachable cover is the practical choice: you wash the cover, never the silk inside.
6. Size and drape. Match the comforter to your bed, and allow a little overhang on the sides. A duvet that barely covers the mattress will feel small no matter how good the filling is.
7. Beware of “silk-like” marketing. Words like “silky,” “satin,” or “silk-feel” on a label usually mean synthetic fiber. Real silk says so plainly: “100% mulberry silk” or “100% tussah silk.”

The short version

Mulberry silk is the luxury option: softer, smoother, whiter, longer fibers, and a higher price. Within mulberry, double-cocoon is the strongest and warmest choice for a duvet, while single-cocoon is the softest. Tussah silk is the value option: genuine silk, slightly firmer, naturally golden, and easier on the wallet. Both will sleep cooler than down and lighter than cotton, and both will last for years if you wash only the cover and let the silk do what it does best.

If you want the softest summer duvet and don't mind the premium, pick mulberry. If you want real silk filling at the best price, tussah will not disappoint.