Silk rug cleaning

A fibre with no scales and no grease

Wool is a scaled fibre coated in lanolin. Silk has neither: it is a smooth, continuous filament of triangular section, and it is that section that returns the light directionally — the shimmer, that way a silk rug has of changing colour as you walk around it.

Two consequences, one reassuring, the other not. Reassuring: with no scales, silk does not felt. There is no irreversible shrinkage to fear in the bath. Worrying: with no lanolin, nothing repels water-based soiling. A spilled liquid does not bead for a second as it does on wool, it goes straight in. And with no protective cuticle, the visible surface is the fibre itself — everything that damages it shows.

Alkalinity attacks the fibroin

Silk is made of fibroin, a protein. Like the keratin of wool, it degrades in an alkaline medium, and it does so faster: the working window is narrower still than for a wool rug. Beyond pH 8, the fibre loses strength, yellows and loses its sheen.

In other words, everything to be found under the sink is disqualified: washing powder, degreaser, household cleaner, carpet shampoo, and above all percarbonate, which is both alkaline and oxidising. On silk, a single application is enough to dull a whole area. We work with neutral soap, in cold water, and we rinse until complete neutrality.

Rubbing dulls silk, and it is permanent

What felting is to wool, abrasion is to silk. A brush, a sponge rubbed across it, the rotating brush of a vacuum cleaner or simply repeated traffic in the same place fibrillate the filament: it splits into microfibres that no longer return the light along the same axis. The area turns dull and whitish, and reads as a pale stain although no colour has moved.

That is why a silk rug is never brushed. We work by hand, flat, in the direction of the pile, and lay the fibres back down with the flat of the palm rather than with a tool.

The same logic applies to stain removal: on silk, local stain removal almost always leaves a visible ring, because the water changes the way the treated area returns the light. Where we would spot-treat a wool rug, we wash a silk rug as a whole.

Hereke, Qom, Kashan — and the false silks

The silks that come into the workshop are mostly from three families. Hereke, in Turkey: fine silk, very high density, a name so well known in Belgium that one workshop made it its shop sign. Qom, in Iran: very fine small formats, often in full silk. Kashan: silk as well, with its hunting scenes. The knotting density of these pieces goes beyond 500,000 knots per square metre, and can approach a million.

There are also rugs sold as silk that are not: Indian and Pakistani copies sometimes use artificial silk, that is to say viscose. It is cellulose, not a protein. Wet, viscose loses most of its strength, lies down, yellows and stiffens — a wash carried out as for true silk can ruin it. Identifying the fibre is therefore done before the water, never after, and it is part of the diagnosis.

The workshop protocol

Dusting by gentle suction, with no beating: a fine silk is not struck. Colour-fastness test, run for longer than on wool — up to an hour under light pressure on an old piece — and fixing of the dyes if the cloth talks.

A short bath, in cold water, with neutral soap. No brushing, no prolonged soaking. Copious rinsing until neutrality, measured spinning, then flat drying, in the shade and in a ventilated atmosphere: direct light yellows silk, and slow drying lets the dissolved soiling rise back up as a ring.

Between washes, care comes down to three things: vacuum without a rotating brush, never leave heavy furniture standing permanently in the same place, and keep the piece out of direct sunlight. A silk rug laid under a south-facing window loses its colour before it loses its pile.