Silk
A protein fibre like wool, and subject to the same alkali, enzyme and bleach restrictions — but CleaningHQ has not verified a silk-specific authority.
What not to do
Best avoided
The available guidance advises against this.
The failure modes are listed rather than implied: shrinkage, fading, dye bleeding, loss of shape, and a limp or rough texture.
Why we say this
Supported
Recorded as may damage at avoid rather than unsafe on: the body advises against home washing and describes what goes wrong, rather than stating that water destroys silk.
Sources
Drycleaning & Laundry Institute International (DLI) · Trade or professional body
Relied on for: That silk is highly sensitive to moisture, that washing it at home can cause shrinkage, fading, dye bleeding, loss of shape and a limp or rough texture, and that silk generally responds best to professional drycleaning. (states this directly)
Verification: a person has read the passage relied on.
Read on — The whole page: fibre character, home-washing risks, dye bleeding, perspiration. Supports a narrower statement — our claim was reduced. This closes the silk gap open since Sprint 3, but narrower than CleaningHQ had hoped. The silk record can now rest on a professional body for the practical guidance — home washing risks, dye bleeding, chloride from perspiration, drycleaning as the default — but the alkali-hydrolyses-protein mechanism CleaningHQ wanted to state is NOT in this source and remains an interpretation from general chemistry, labelled as one. No bleach position may be attributed to DLI.
Last reviewed by a person on .
Precautions
- Check the manufacturer's instructions
- Test on an inconspicuous area first
In detail
Silk is a protein fibre, built from fibroin rather than the keratin of wool, and it shares the chemistry that governs wool care: proteins are hydrolysed by alkali, cut by protease enzymes, and attacked by oxidising bleaches. On that basis the same restrictions apply — a mild neutral detergent rather than a biological one, no bleach, and gentle handling. CleaningHQ states this as an inference from protein chemistry and says so, having still found no silk-specific fabric-care authority. What it can tell you with authority is where the answer lives. The body that devised the care-labelling system states that a garment's symbols indicate the MAXIMUM SEVERITY of treatment it can withstand without irreversible damage — so on silk the label is not a suggestion to weigh against general fibre advice, it is the specification, issued for that made-up garment including its dyes and finishes. Silk also differs from wool in ways the shared chemistry does not cover: it lacks wool's scale structure and so does not felt, and water spotting on some finishes has no analogue in wool care. Where the label specifies professional textile care, that is the answer.
Properties
Sensitivity
- Alkalis
- Not known
- Chlorine bleach
- Not known
- Heat
- Not known
- Abrasion
- Not known
- Porous
- Not known
“Not known” means CleaningHQ has not established this, not that the material is unaffected.
Why
- Silk is explained by Dye migration and colour bleeding
- Silk is explained by Fibre swelling and shrinkage
Related
- Silk is commonly affected by Perspiration
- Silk is commonly affected by Antiperspirant residue
Hacks and claims involving this
- Oxygen bleach is the wool-safe bleach Does not work
- Dry-clean-only labels are just the manufacturer being cautious Does not work
- Washing silk at home Disputed
- The care label allows oxygen bleach even when it bans chlorine Does not work
- The dots on a care label are just a rough guide Does not work
- A stain method that works on cotton works on anything Does not work
Sources for this page
Sources
GINETEX Technical Booklet — international care labelling system
GINETEX, The International Association for Textile Care Labelling, 2018 · Standards body
Relied on for: That care symbols indicate the maximum severity of treatment a consumer can use without damaging the article, that the labelled processes are intended to avoid any irreversible damage, and that professional textile care is one of the five labelled treatment families. (states this directly)
Verification: a person has read the passage relied on.
Read on — The introduction and implementation section; the definitions of treatments and bleaching agents; and the description of the symbols. Supports a wider statement — our claim was widened. This reverses a Sprint 2 downgrade and corrects an attribution. The chlorine-versus-oxygen bleaching distinction, withdrawn in Sprint 2 because ISO 3758 could not be read, is restored and cited here. More importantly the source model was wrong: CleaningHQ treated ISO 3758 as the authority and GINETEX as a commentator, when GINETEX is the origin and ISO the licensee. The ISO record is now marked as deriving from this one. The 'maximum severity' principle and the definitions of the two bleach classes are new and now carry the laundry vertical.
Kirk-Othmer Encyclopedia of Chemical Technology
John Wiley & Sons · Reference work
Relied on for: That silk fibroin is a protein and that proteins are hydrolysed by alkali and by protease enzymes. (background and mechanism only)
Verification: the work exists and is described correctly. Nobody has yet read the specific passage.
What CleaningHQ cannot answer yet
These are recorded questions about this subject that we have not yet researched to a standard we would publish.
- Compatibility of bleach with silk
Last reviewed by a person on .