How to recognise real silk

Silk is first and foremost a natural fibre. This fibre is spun into yarn, then the yarns are interlaced to create fabric. The weave describes how those yarns are arranged together.

That is why two fabrics can both be silk yet have a very different feel. Silk satin is generally very smooth and slippery, while silk twill offers a slightly more structured sensation. Crepe is more textured, and chiffon is lighter and airier.

The thickness of the yarn, the weight of the fabric and its weave therefore influence the feel as much as the fibre itself.

Silk is generally soft, supple and fluid, but it is difficult to identify with the fingers alone. Some modern polyesters can also be very fine and pleasant to the touch. Touch is therefore a first clue, but not proof on its own.

Silk and polyester can sometimes look alike, but their nature is very different. Silk is a natural fibre of animal origin, composed mainly of proteins. Polyester is a synthetic fibre.

Polyester can imitate some aspects of silk, such as sheen or softness, but its behaviour remains different. Silk generally has a livelier drape, more nuanced light and absorbs moisture better, which makes it more comfortable against the skin.

Polyester, by contrast, often has a more uniform appearance and absorbs very little moisture.

By sight and touch, the difference is not always obvious. Under heat, however, it becomes much clearer: silk burns away, while polyester melts. This is what the burn test makes possible to observe.

Visual and tactile tests provide useful clues, but they do not always lead to a certain conclusion. To go further, you can examine the fibre’s behaviour directly, particularly through a burn test.

At Soie de Siam, every scarf comes with a small sample of the same silk used to make it. It lets you handle or test the fibre without taking a thread from the scarf.

The burn test lets you observe the fibre’s behaviour directly. Three elements are especially revealing: its reaction to the flame, its smell and the residue it leaves after combustion.

A few fibres are enough to carry out the test.

Silk curls up and burns away slowly. Its smell clearly recalls burned hair. It leaves a dark, brittle residue that crushes easily once cooled.

Polyester melts under heat and generally forms a small hard residue as it cools. Its smell is more chemical, and the residue does not crumble like silk’s.

There is no fibre officially called “fake silk”. This expression generally refers to materials used to imitate the appearance or feel of natural silk.

Polyester is one of the most common. It is a synthetic fibre that can be made into a smooth, shiny and fluid fabric.

Viscose, made from regenerated cellulose, can also recall silk through its drape and softness. It belongs to the family of rayon fibres — often called rayon in English.

The term “artificial silk” was historically used to describe some of these fibres, especially the first rayons, because they sought to reproduce the appearance of silk.

No. Silk describes a fibre, while satin describes a type of weave.

Satin can therefore be made from genuine silk, but also from polyester, viscose or other fibres.

Charmeuse, for example, is a light, fluid satin that is generally shiny on the right side and more matte on the reverse. Silk charmeuse is therefore charmeuse made with silk yarns.

The same is true of twill, or serge: it is a type of weave. A silk twill is simply a twill-woven fabric made with silk yarns.

Seeing the word “satin” on a fabric is therefore not enough, by itself, to tell whether it is silk.

In Thailand, some commercial names can easily be confusing when you are unfamiliar with the local textile market.

For example, fabrics sold as “Italian Silk” or ไหมอิตาลี can be found. Despite what the name may suggest, they are not necessarily natural silk or made in Italy. This name can in particular refer to polyester fabrics.

You may also come across terms containing “silk” or “satin silk” even though the composition is synthetic.

That does not mean these terms have the same meaning everywhere: genuine silk satin does, of course, exist. The Thai example simply shows why it is important to distinguish the commercial name of a fabric from the fibre it is actually made of.