No. Rayon is regenerated cellulose made from wood pulp, invented as a cheaper substitute for silk and long sold as artificial silk. Real silk is the natural protein filament spun by the silkworm. They can look similar but are entirely different fibers.

How can I tell silk from rayon?

Silk is warm to the touch, very strong, and keeps its strength when wet, with a deep soft luster. Rayon feels cool, drapes well, but weakens noticeably when wet and is generally less strong. A burn test is definitive: silk smells of burnt hair, rayon of burning paper.

Which is more durable?

Silk, especially wet. Rayon loses much of its strength when wet and is more prone to shrinking and losing shape, which is why many rayons must be washed gently or dry cleaned.

Side by side

Silk vs Rayon

Silk and rayon look alike in a shiny blouse because rayon was invented to imitate silk, but one is spun by a silkworm and the other is wood-pulp cellulose dissolved and respun in a factory. Silk is the natural protein filament: strong, breathable, temperature-regulating, and costly. Rayon is the first manufactured fiber, silky and drapey and cheap, but weaker (especially when wet) and less durable than the cloth it imitates.

Silk

No. 128

the filament fiber, often woven satin or plain · first documented Antiquity

Rayon

No. 119

woven from regenerated cellulose · first documented 1890s

The differences

Aspect	Silk	Rayon
Origin	A natural protein filament from the silkworm's cocoon.	Regenerated cellulose: wood pulp dissolved and respun (artificial silk).
Strength	Strong for its weight, even when wet.	Weaker, and notably weak when wet.
Comfort	Breathable and temperature-regulating; warm in cold, cool in heat.	Breathable and absorbent, with a cool hand, but less regulating.
Sheen	Deep, soft, natural luster.	Silky and lustrous, often a touch flatter.
Care and cost	Delicate and expensive; often dry-clean.	Cheaper, but can shrink and weaken; many rayons need gentle care.

Which to choose

Choose silk for natural luxury, strength, and temperature regulation, at a price. Choose rayon for a silk-like drape at a fraction of the cost, accepting that it is weaker, especially wet, and more delicate to launder. Rayon captures silk's look but not its resilience.

Common questions

Is rayon real silk?: No. Rayon is regenerated cellulose made from wood pulp, invented as a cheaper substitute for silk and long sold as artificial silk. Real silk is the natural protein filament spun by the silkworm. They can look similar but are entirely different fibers.
How can I tell silk from rayon?: Silk is warm to the touch, very strong, and keeps its strength when wet, with a deep soft luster. Rayon feels cool, drapes well, but weakens noticeably when wet and is generally less strong. A burn test is definitive: silk smells of burnt hair, rayon of burning paper.
Which is more durable?: Silk, especially wet. Rayon loses much of its strength when wet and is more prone to shrinking and losing shape, which is why many rayons must be washed gently or dry cleaned.

Full entry: Silk Full entry: Rayon

Sources & References

1.Silk, Wikipedia
2.Sericulture, Wikipedia
3.Rayon, Wikipedia
4.Viscose, Wikipedia