Real silk or not? Know what you're buying

Here at Sartor, when we talk about silk, we mean natural silk. That is just what you would expect – silk obtained from a natural source, the cocoon of the silk moth. Most often that’s the mulberry silkworm, although there are other varieties that give us silk. Simply put though, the fibre is made entirely by mother nature.

For the whole, fascinating story on natural silk, check these out:
 

However, in most shops you are far more likely to encounter artificial silk than the real thing. “Art silk" is just a pretty name for fabrics made to mimic silk in appearance, sheen and drape but using other materials, usually rayon or polyester. The “art” in art silk has nothing to do with Michelangelo. It is an abbreviation of “artificial.”

The main advantage of artificial (or art) silk is its affordability, but it lacks those core qualities that make natural silk so special, its softness, delicate sheen, light weight, and breathability.

In other words, art silk is artificial silk, man-made materials created to look like natural silk. Art silks include viscose silk, acetate silk, synthetic silk, and chemical silk, with all their shifting definitions.

By the 1960s textile fibers were divided into natural and chemical by origin. Natural polymers would include filaments made of cellulose and proteins, while synthetic polymer filaments would be polyamides, polyesters, polypropylenes and others.

That is pretty much the way things are today, except that the list of polymers and how they are produced continues to grow. Cellulose now gives us a whole range of great materials, like modal and EcoVero, while synthetic polymers include functional fabrics for all sorts of uses.

Chemical fibers, such as viscose or polyester, are used to make infinite filaments. In nature, the closest thing to an infinite filament is natural silk. And, really, compared to the relatively short fibers of cotton and wool, silk filaments seem to go on forever – they can be over half a mile long.

Adding the fact that chemical fibers can be made to resemble real silk in fineness, smoothness and luster, we get the confusion that has persisted to the present day. 
These never ending chemical filaments were generally referred to as “silks” due to their resemblance to silk. Of course, they aren't silk any more than corn silk is.

It stands to reason that when people were looking for a handy way to describe the smooth, silky fabrics made with these smooth, silky filaments, they simply called them “silk” too, with or without a modifier.

Terms such as “polyester silk” and “acetate silk” were not necessarily an attempt at deception, just an early shot at describing a product that people were not yet familiar with. 

Merchants still do this today. So, if you are shopping for natural silk and you want the real thing, always check the fiber content tag (both for clothing and for by-the-yard fabric).

All textiles must carry a fiber content tag that gives their material composition. And each fiber has a legally defined name.

If the merchant does not list fiber content for the fabric you’d like to buy, that’s a red flag.

It could be an innocent oversight, but it could also be an attempt to mislead you. 

The product name itself is not strictly regulated. There is some leeway there – you can advertise an "art silk dress" and a "silky gown.” But the fiber content is another matter; that must be precisely labelled using the agreed upon fiber names – for example, viscose, acetate or polyester.

Only fiber derived from the spinning glands of an insect may be labelled as silk. The word silk cannot be used for any other material. The content label of a product made of pure, natural silk may read either “100% silk” or simply “silk.” Either way, it must be natural silk.

The same rules apply throughout the European Union. If buying fabric in any EU country, you can check the relevant language version of Regulation 1007/2011. In Germany you will see 100% Seide, in the Czech Republic 100% hedvábí, and so on.

Never base your purchase just on the product name or description, always check the fiber content tag and if it’s missing, ask.

Let’s say you’ve got something in your shopping cart called “Silky midnight satin.” 

It makes sense that the product name is written to evoke the beauty and magic associated with natural silk, but the reality is probably elsewhere. After all, “silky” only means “smooth like silk.” 

Check the fiber content. Your “Silky midnight satin” It may be pretty, but chances are it’s polyester and won’t breathe at all. Think twice before making a summer cocktail dress with it.

Silky synthetics are not much suited for the summer heat. When temperatures rise, choose natural silk or a breathable rayon instead.
 

AsIn recent years, Europe has succeeded in making product labeling far more reliable. If a label says “silk” then you can bet that’s what it is. But buyers in other regions should exercise some caution. 

In some countries, the term “silk” is used very loosely and may be applied to anything that remotely resembles silk.

It can easily happen that you order silk through a discount web portal somewhere in Asia and end up, weeks later, with a pouch full of polyester.

In China, the term silk is not strictly regulated. The Chinese symbol for silk 丝 (pronounced “s”) also means filament, whether it’s natural silk or not. I could write a whole post on all of the “silk markets” we made the rounds of on our early trips to China in search of natural silk suppliers. It would be funny if it weren’t so sad.

In India the term art silk is popular. It gives the impression of some kind of artistically enhanced silk, but it is nothing more than an abbreviation of artificial silk.

Milk silk is another form of faux silk. It is a soft, functional knit that is very comfortable to wear. It is not, in spite of what the name suggests, made of milk proteins. It is a polyester microfiber.

Then there’s ice silk, which is named for its cooling effect. This also has nothing to do with natural silk. It is made of cellulose.

So there you have it. Once you know the traps and pitfalls of product naming, you should be able to shop confidently. Good luck out there!

Got any art silk in your closet?

Ever brought home fabric that wasn't what it let on to be?

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