The physical process of cleaning or washing textiles can damage them. Every time a textile is washed, it suffers a degree of loss as broken or loose fibres are rinsed away. Some cleaning methods are harsher than others. The most damaging are tumble action machines, whether domestic washing machines or commercial dry cleaning machines. Their beating action damages and breaks fibres, whilst spin cycles crush them.
If you wish to preserve your textiles, you need to avoid or minimise the need to clean them. It is important to prevent dirt accumulating rather than causing unnecessary damage by repeated cleaning treatments. Not all textiles were originally intended to be washable. Undergarments were often used to protect expensive outer garments from body stains, for example. These undergarments were intended to withstand laundering, unlike valuable silk and velvet outer garments.
Wet cleaning or washing
The most familiar method of washing everyday textiles is to use water and detergent. The urge to wash historic textiles can be as automatic as the machines used. Historic textiles should not be regarded as laundry, however, because wet cleaning can do a great deal of damage to them. Water can cause cotton and linen to shrink, especially when combined with heat. This shrinkage does not just reduce length of yarn, but also tightens the weave of the fabric, causing stress and distortion. Similarly, wool can shrink or become irreversibly matted, while if dyes in a textile are not 'fixed' they can run, damaging adjacent areas.
Textiles are markedly weaker when wet and therefore much easier to damage or tear. In some cases, light finger pressure when trying to manipulate or handle a wet historic textile is enough to split the fabric. Finally, many textiles shrink and distort as they dry. For all these reasons, wet cleaning of historic textiles should only be undertaken by a textiles conservator.
Water damage & spills
Try to limit the damage by drying the textile as quickly as possible. Blot off excess water with white towels or white kitchen paper to absorb as much moisture as possible, repeating the process with clean towels or paper until all the moisture has been removed. Textiles are much weaker and more easily damaged when wet, so treat them gently. Avoid the temptation to wring out excess water, or press down hard on the textile as you blot.
The next step is to circulate cool air around the textile to dry it. The aim is to have a gentle current of cool air all round the fabric. Desk top fans are good for this, but should not be pointed directly at the textile. It is possible to use a hairdryer, but it must be set on cool, as drying with hot air can easily cause shrinkage and make the problem of running dyes worse. Contact a textile conservator as soon as possible if your textile has significant monetary or sentimental value.
The damage caused by choosing the wrong cleaning method can be irreversible. Seek advice before you start, rather than calling a conservator after the damage has been done.
The safest way to remove loose dust and dirt is by vacuuming. Avoid blower machines because they will drive dirt deeper into the textile. Examine the textile carefully to establish whether the textile and trimmings are robust enough to vacuum - look for loose fibres, tears or areas where the fabric seems fragile. If an embroidery thread is loose, for example, strong suction can unstitch an entire area.
It is easy to accidentally vacuum up and lose sequins or beads from the textile. There are two ways of preventing this type of damage. The first is to cover the nozzle itself with muslin, fine net or stocking, which can be held on with an elastic band. For larger flat textiles, a net mesh or muslin screen can be used instead. These often have a wooden frame, such as those used for embroidery, to hold the mesh. The frame is placed gently onto the surface of the textile, which is then vacuumed through the screen. Remember to lift the frame to move it to the next position, as sliding can scuff the surface of the textile. Hold the vacuum cleaner nozzle 5-10cm above the textile to prevent scuffing and to reduce the suction pressure.
If there are raised or three dimensional decorative elements on the textile, for example flowers on a hat, a soft brush can be used to lift dirt from crevices towards the covered nozzle. Small attachments, such as those with soft brushes normally sold for vacuuming computers, can be used for corners and crevices (supplier: Preservation Equipment).
Dry cleaning is often used for cleaning delicate fabrics in the belief that it is a gentler process than washing with water. In fact, dry cleaning is quite a rough treatment that can cause significant wear and tear. Commercial dry cleaning is not usually appropriate for historic textiles that you wish to preserve.
Dry cleaning uses solvents to remove oily dirt and to clean water-sensitive fabrics such as silk and wool. The most common solvent used in commercial dry cleaning is perchloroethylene, which is particularly effective for removing oily dirt. Dry cleaners use this solvent in large tumble action machines on a fixed time cycle. The machines usually take loads of 10 to 20 kgs. For commercial reasons it is unusual to solvent clean single items, so the cycle is geared to an 'average' requirement. A greying effect can be the result of deposition of dirt from other items in the machine, or from recycled solvent that has not been adequately filtered. The fixed cycle means that staff cannot stop the machine even if they notice a problem, such as dye running. Once a cleaning cycle is complete, the solvent is drained and heat used to speed evaporation of solvent from the textiles.
Traditional cleaning remedies should be avoided
Several traditional remedies applied to textiles in the past actually contributed to their demise rather than extending their life. Early 'dry' cleaning used an absorbent powder, such as Fullers earth (a natural clay that is slightly alkaline) bran or cornmeal. The powder was worked into the textile and then brushed away in the hope that it would absorb and remove oily stains. Bread, lightly rolled over a textile, was also recommended to removing grubbiness and surface soiling.
The problem with all of these remedies is the residues that are left behind. At best, residues of Fullers earth will themselves become a dirty mark, whilst at worst they can react with alkaline sensitive parts of the textile. Residues of bread, bran or cornmeal will attract and nourish insects and vermin and encourage mould growth in damp conditions.
Milk was also popular for a wide range of fabric treatments, from removing mildew, cleaning kid gloves or preserving lace. There are inevitably a few cases when milk, which is an oil-in-water emulsion, will be effective. In most cases, however, milk will cause all the problems associated with water, such as colours running, as well as causing permanent stains if it is not thoroughly rinsed away. In addition, residues will provide a tasty source of food for mould, insects and rodents.