Important note: Please read the entirety of this article on how to care for silk before you attempt anything with your objects/items of clothing/etc. I cannot and do not endorse DIY conservation by untrained individuals. If you feel unsure about how to do things, be aware that there is always a possibility that you could be doing irreversible damage. Do not experiment with objects that are especially valuable to you. Read the suggestions carefully and find a commercial or professional specialist to care for your items if you don't feel prepared to risk the consequences of your own actions.
- Think like a conservator
- What is silk?
- What have you really got?
- Why is it important to know what you have?
- How are you using your silk?
- What does this mean for how you care for it?
- If you have a traditional, insect-based silk
- If you have a plant-based silk ("bamboo silk", cellulose or rayon, or cotton)
- If you have a "plastic" silk (polyester, cellulose)
- If you use your item a lot
- If you store your item a lot
- Other general guidelines
- Thoughts on mechanical cleaning
- Thoughts on washing
- Thoughts on commercial dry cleaning
- Conservation approved resources to find out more about caring for silk (and textiles)
- Find out more
Think like a conservator
A conservator, that is, a person whose professional job is to care for material cultural objects or buildings (and not a person who saves whales), will have a very particular way of looking at items and how they degrade.
Before you begin thinking about how to care for your silk, there are some important and fascinating questions that you should think about first. I will only give you some examples, as once you get the gist of this, you will be more than capable of coming up with more questions yourself.
- Is this really silk? Where did I buy it? Do I think it's silk because I was told so or because it's on the label? Or is it because it comes from a company I trust, and they have assured me this is silk. If this is indeed silk, what kind of silk is it?
- How do I use this? Is it every day, like in a bedsheet or pillowcase? Is this a fancy dress or tie we only wear every now and then? Is this underwear?
- How do I normally store this? Do I fold it? Do I set it out straight? Do I put it in cupboards or just on top of a shelf?
- How is the climate inside my house or space where I store my silk? Is it dark or well lit? Is it damp? Does it smell mouldy there? Is it dry? Do I see tons of moths flying around?
What is silk?
If we're talking about the real thing, silk is a natural fibre composed of proteins, like your hair. While your hair is mostly made up of a protein called keratin, silk is made up of a protein called fibroin.
As you probably know, natural silk is mainly produced by insects (although arachnids make silk spiderwebs too). In fact, check out this surprising article about an extremely rare cloth made of spider silk.
The real deal. Mulberry worm farm and cocoons. Photo by Quang Nguyen Vinh from Pexels.
Rare spider silk aside, the one we commonly use for clothing is made by the mulberry silkworm, which is ultimately a moth larva. The larva secretes the silk slowly as it builds its cocoon. The silk is taken from the silkworm's cocoon, which is boiled (with the larva still inside) so that the silk thread can be unravelled in a single piece - which explains why animal rights activism does not condone natural silk. The cocoons are boiled because having a single piece of thread is important for the strength of the ultimate fabric. If you did not know this and you like animals, larvae included, maybe consider sticking to artificial or plant-based silks.
What have you really got?
The first thing you need to figure out is if what you have is really, actually silk and not synthetic silk. Traditional silk, as we said above, is an animal-made protein fibre.
This amazing blouse with an escape map from the National Air and Space Museum, which you can see here is described as a silk fabric, but in the materials list you will only see rayon, plastic and thread. Artificial silks can be seen from the late 19th century onwards.
Artificial silk, art silk or synthetic silk is, generally speaking, a plastic. That means it will, most likely, be a petroleum or cellulose based spun polymer. Depending on how old or modern your "silk" is, it could be anything from cellulose to rayon (both also called viscose) to nylon to cotton to polyester or a blend of any of these. Lately, it could even be made of cellulose extracted from bamboo, which would effectively make your "silk" a plant-based fibre. Lately, I have seen bamboo viscose used for hypoallergenic orthopedic pillows.
I even found a small article on research into artificial silk made by bacteria. This article is from 2018, so I'm not sure if they've now figured out how to mass produce bacteria-made silk without using the intense corrosive solvents, but maybe they have and you have some now! ? If you do, you can probably treat it as if it were a regular protein silk.
Why is it important to know what you have?
The things that will hurt or help your "silk" will be dependent on what materials we are talking about. As you have now seen, you either have an animal protein, a petroleum-based plastic or a plant fibre. We will talk about this further below.
How are you using your silk?
Aside from knowing what your "silk" actually is, have a think about how you use it.
- Wear and tear will obviously be worse on items you use a lot.
- On the other hand, if this is an item you only wear on special occasions or it's an heirloom like a wedding dress, then you have to worry about how it's being stored.
- In those cases where you actually wear the items occasionally, it is important to remember not to store it dirty since, if you have a real animal protein silk, sweat or other organic stains will only make your silk much more palatable and attractive to pests.
What does this mean for how you care for it?
The following information has been obtained from the Canadian Conservation Institute Notes. The Canadian Conservation Institute is a recognised and respected institution in the field of conservation.
If you have a traditional, insect-based silk
- Whenever possible, avoid high temperatures. 30°C (85°F) will accelerate the rate of degradation. 20°C is much better to reduce decay over time. If it is difficult for you to artificially change the temperatures in your home, increase ventilation and choose the best space in the house for your storage. Don't put it in the hottest room you own.
- The protein will attract clothes moths and carpet beetles. Keep an eye out for cases and insects in your closets and drawers.
- Protein-based silk will yellow in the sunlight and is particularly sensitive to UV. Do not let direct sunlight to fall on your silk for extended periods of time.
If you have a plant-based silk ("bamboo silk", cellulose or rayon, or cotton)
- Even if your silk isn't protein-based, there will be other insects that like cellulose and will come for your silk as well. Keep your spaces clean and have a look out for frass (insect poop pellets or powders), holes or abraded areas on your silk that could indicate an insect has been grazing on it.
- Note that if your silk is being termed "bamboo silk", you can still think of it, in some ways, as a plastic because the bamboo cellulose is being turned into a spun cellulose polymer to make the threads - with the main difference being that instead of getting the cellulose from wood or cotton, it is coming from bamboo.
- If what I have read here is true of viscose rugs, you might have to be extra careful when thinking about washing.
If you have a "plastic" silk (polyester, cellulose)
- Plastics are a very tricky material. Over time, many of them have proven to be rather problematic when it comes to surviving the ages. You may have noticed this with plastic items at home such as remote controls that become sticky.
- If you have a synthetic "plastic" silk, it will not directly attract insects, although if you store it without cleaning, they might still damage your object by grazing on the sweat or other organic stains you left on it.
- Plastics are sensitive to UV and light, so just like with the animal and plant based silks, it's best to reduce exposure to sunlight.
- Plastics are also very sensitive to high humidity and heat, so although the reasons behind it may be different as for the plant and animal based silks, it is still a good idea to keep your storage cool and not very humid.
- Plastic decay can also be accelerated by atmospheric pollutants such as sulphur dioxide and nitrogen dioxide. If you live in a city or in an area with high pollution, it wouldn't hurt your items (and your own lungs too) to have an air purifier in the room. You can also look into scavenger materials such as the activated charcoal cloths we use to protect silver items to try to absorb some of these pollutants before they come into contact with your object.
- As plastics degrade, they can lose the plasticiser in them that made them soft or pliable by evaporation or straight up weeping. This means that they get more and more brittle over time. If you fold your items, the folded creases may develop into breaking points. Be aware of this when you store.
- If you have a "plastic" silk, that is very degraded, any washing with water or even solvents could destroy it, so beware of that before you try it and contact a professional conservator first.
- For more information on modern materials and plastic deterioration, read here.
- You can also read this article on conservation of plastic objects to get an idea of how tricky plastics can be.
If you use your item a lot
Naturally, there is no reason to expect you to treat your favourite silk scarf or pyjama as a museum object, especially if it's relatively new. This doesn't mean you don't want it to last as long as possible. That's why you're here, after all.
- Be gentle with your silk. Regardless of whether it is plastic, protein or plant based, try not to fold it into hard angles. If you like scrunching it up or making very fancy knots with it, be aware that over time, this could create structural damage.
- If you decide to wash your silks at home because they are relatively new and undamaged and can take a bit of washing, be very gentle. Don't scrunch it up in your hands and rub it together against itself. See the notes below on washing as is used for museum textiles for the gentlest procedures.
- If you'd rather send your silks off to commercial dry cleaning services, make sure first that 1) they know how to treat silk and 2) you know what kind of silk you're giving them. They probably know what they're doing, but making sure it's an explicit thing they know about won't hurt you at all.
- Generally speaking, if your silk is a "plastic" based, completely modern, bought-it-last-year type of silk, it's probably okay to wash it at home rather than send it to a dry cleaner. Remember that dry cleaners use mechanical tumblers and sometimes a lot of heat. Plastics + a lot of heat could end up badly. Beware of that with your viscose and non animal silks.
- Do not iron your silk. If you have protein silk, think of it as hair. Too much ironing and your hair starts looking like hay. Excessive direct heat will damage the proteins. If you have a cellulose based silk, it will probably be more resistant to heat (a little bit like cotton), but don't overdo it - remember that cellulose is still a kind of plastic. If you have a synthetic, plastic silk, direct ironing heat is probably a bad idea. You could use a steamer at a safe distance.
- If you have silk bedsheets or pillowcases, it becomes a matter of finding the balance between overwashing and overusing. This will be a personal choice, but it seems 1-2 weeks is the recommended period, unless you had some serious soiling, in which case, washing is probably in order. Keep in mind that you will not be able to wash your sheets in the same way that you wash regular bedsheets as silk will require more delicate care, separate loads, special detergent, etc. You also don't want to keep sleeping on dirty sheets just because you're scared of damaging the silk through constant washing.
- Don't overdo the soap or detergent. More soap does not mean more clean. If anything, excess detergent will require more effort to wash it out, which means more mechanical stress on your silk. Additionally, if you fail to remove it completely, the residual detergent left behind in the fabric can cause long term damage because silk is sensitive to strong alkalis (so avoid bleaches too).
- While I would not recommend going all the way with distilled water and conservation soaps for things as big as bed sheets, you might want to do it for smaller items like scarves or handkerchiefs if they are something you really care for.
- Make sure you read the instructions carefully. It is very likely that if you are spending the money to buy a silk product, the seller will be giving you washing instructions on the labels. If they are not, maybe wonder about what they're selling you and how much they care (or not) about your product lasting you a decent amount of time.
- When hanging out your silks to dry, remember that silk (and plastic) is sensitive to UV. Direct sunlight may feel like the fastest way to dry, but it will also expose your silk to a lot of light damage. Try to dry your silks in a shaded, but well ventilated area.
If you store your item a lot
- If you keep your items mostly stored, flat storage will be much better than rolling things up or folding too much. Just like when you fold a piece of paper, when you fold a textile, it may develop wrinkled and weak spots in the folds. These fold areas may eventually become breakages if your silk dries up and weakens over time. Folding also means that you give insects really cozy nesting crannies and that you may miss any damage because you can't see it.
- Do not use anything other than acid-free tissue paper to wrap your silk items. Coloured papers could end up accidentally transferring dyes to your objects. Acidic papers will only increase the degradation rates.
- If you have any notes or papers with pins or clips or staples associated to your silk object, don't put them against the fabric. Any rust on the metals will stain. Similarly, do not store other metal objects in direct contact with them - think pins, cuff links, tie bars, etc.
- If possible, do not stack your silks on top of each other unless they are in separate boxes. The accumulated pressure can damage them over time.
- Read more on storage guidelines here.
- If your item smells musty or you suspect mould, it probably means that the place you are storing it in is too damp. Dry out your object and ventilate it to prevent further mould proliferation. Do not put it against your nose "to make sure" you are smelling correctly. You don't want to be inhaling active mould spores. Once your object is dry, you can try to vacuum it gently, preferably with a vacuum with a HEPA filter and adjustable speed set to the lowest available. It is best if you put a mesh over the vacuum hose mouth so you don't accidentally suck in your object. Once it is clean, you may look into washing or dry cleaning. See below for information on that. Important: If your item is mouldy and you vacuum it out, remember that vacuums push out the air that goes in. If your vacuum does not have a good HEPA filter, then it is possible that all the mould particles you are vacuuming are just coming out the back and you are breathing them in. Make sure you have the right sort of vacuum before trying to clean up mould. Also, once you have cleaned your item, don't just put it back into the mouldy cupboard. Make sure you sort out the dampness problem in the storage space, or you'll just have to do it all again next time.
Other general guidelines
According to the Canadian Conservation Institute (CCI) Notes on preventive care for textiles and fibres, which you can read here, generally beware of the following:
- UV and light will fade dyed silks over time. They will also break up the structure of the silk. It would be best to keep them in the dark.
- Even if your silk is plastic-based, soiling will attract insects. Store your items clean.
- Generally speaking, try to avoid relative humidities that are below 40% or above 70%. Too much humidity can foster mould growth and attract insects. Too low humidity will embrittle your silk. If your silk feels brittle and crackly and dry, refrain from handling it a lot. You will probably not be able to wear it anymore as it will just break apart. At this point, and if the item is very special to you, consider finding a specialist to consolidate the object and give you specific guidelines on how to store it properly.
Thoughts on mechanical cleaning
When we talk about museum objects, any type of cleaning or washing is considered a destructive activity which must be approached with care and a throrough decision-making process. This may sound odd, but if you think of cleaning as a completely irreversible removal of potential evidence, then it makes more sense. This, of course, may not necessarily apply to your personal objects. Still, it may be worth considering just in case you think you have something of historical or artistic importance.
- Mechanical cleaning means that there is no water or solvent or soap or any of that involved. It's just brushes and vacuums and other mechanical tools to remove dirt.
- Mechanical cleaning will work for dust and surface dirt. It will not remove stains including sweat, blood, food, wine, urine, etc.
- To find out more about mechanical surface cleaning of textiles, go here.
Thoughts on washing
There is a lot that can be said about washing, but here are some points:
- Fragile, fragmented or brittle silks (or other objects) should not be washed. Water is a polar solvent, which means it will just break your object apart even faster. If you have an old heirloom or grandma's wedding dress or great uncle's tie or something along those lines, do be careful and consult a professional before you try anything. Sometimes objects look fine until you touch them and then all hell breaks loose.
- Only wash a silk item if it is in sound condition, still feels soft and pliable and does not feel like when you fold it, it retains wrinkles.
- Washing is not carried out in the same way in conservation as it is in other contexts. When we say washing, we do not mean grabbing the fabric in your hands and squelching it or rubbing it into itself.
- For detailed information on washing, see this note by the CCI. You do not have to follow it to the letter, as you will not be washing museum textiles, but you will get a good idea of the type of care that is required.
- Never store your silk wet or damp. Make sure it airs out properly before putting it away or it might get mouldy and attract insects.
Thoughts on commercial dry cleaning
- Dry cleaning means that they do not use (much or any) actual water to wash your items. This techincally means that your items do not get "wet" because the word "wet" in a technical sense refers to water. This does not mean that your objects will not be submerged or treated with other liquids - i.e. chemical solvents (Tetrachloroethylene, also known as perchloroethylene, or perc).
- If you decide to send your silk to a dry cleaner's to be done professionally, make sure the company you use has experience with silk. Commercial dry cleaning involves a lot of mechanical tumbling and heated cycles to remove the solvents used, so make sure your object is sturdy enough to be able to take that kind of "abuse". Make sure that you are not sending them a painted or dyed silk that will get accidentally bleached or bleed in the solvents used.
- Get more information on dry cleaning for silks here.
Conservation approved resources to find out more about caring for silk (and textiles)
- Notes on Textile Conservation by the Nautical Archaeology Program Conservation Research Laboratory at Texas A&M University
- Notes on stain removal by the Smithsonian Museum Conservation Institute.
- Conserving Textiles: Studies in honour of Ágnes Timár-Balázsy
- Caring for textiles and costumes by the CCI.
- Caring for your textiles by the Victoria & Albert Museum.
- How to check objects for insect infestation
- Insect Pests in Historic Houses and Museums by English Heritage.
- Crighton, J.A. 1993. Silk: A Study of its degradation and conservation. In N. Tennant, ed, Conservation science in the UK: Preprints of the meeting held in Glasgow, May 1993. London: James and James Science Publishers Ltd: 96–98.
- Hansen, E. F. and H. Sobel. 1992. Effect of the environment on the degradation of silk: A Review. In Textile Specialty Group postprints. Papers delivered at the Textile Subgroup Session, AIC, 20th Annual meeting, Buffalo, N.Y., June 1992: 14–30.
- Kuruppilai, R. V., S.P Hersch, and P.A. Tucker. 1986. Degradation of silk by heat and light. In H. Needles and H. Zeronian, eds. Historic textile and paper materials: Conservation and characterization (Advances in chemistry series 212). Washington, D.C.: American Chemical Society: 111–127.
Find out more
If you liked this article and would like to find out more, here are a few things you can do:
- Follow me on Twitter. I will be posting regularly on themes I notice you would like to hear about.
- Join the Reddit community for r/ArtConservation. There are conservators there (myself included) who will be able to guide you. Please note that conservation professional bodies consider it borderline or even outright unethical to give out DIY advice on how to fix things because of the high risk of accidental failure by an untrained individual, so the advice you get will be guidance about preventive steps to take or people to contact rather than how to fix things.
- Consider taking a course for beginners on preventive conservation, such as the one I have here.
- I trained as an objects conservator. I am not a textile specialist. If you would like to talk to a textile or costume specialist, make sure you check out the AIC and ICON lists of conservation professionals to find someone who can help you. AIC is for the US. ICON is for the UK. Your country may also have a local register which is probably Googleable.
If you liked this post, you can follow me on [Twitter](https://twitter.com/ConservaLlama) where I'll be posting more content on conservation tidbits and how to improve your collections at home.