Intelligent use of drycleaning chemicals is one of the three key skills required by the professional cleaner (the others being correct drycleaning machine operation and pressing techniques).

Applying pre-treatment detergent to stains is no substitute for correct stain removal. Leaving pre-treatment detergent on the item to be flushed off in the machine cycle increases the risk of a patch of colour loss. Pre-treatment detergent helps bring a little moisture to areas of collar grime and cuff soiling. It will reduce the risk of localised greying if applied sparingly to areas treated with stain removal reagents and flushed with water or steam.

Most cleaners have a kit of proprietary reagents for taking out specific types of stains but these only work if the cleaner can determine the group to which a stain belongs. Protein stains are caused by substances, such as cream, meat juice gravy perspiration and urine, which derive from animals or humans. The protein remover is mildly alkaline for this purpose.

Stains from red wine, beer, whisky, beetroot and blackcurrant contain vegetable colourings that dye the yarns. These cannot be removed but must be rendered colourless by bleaching. A tannin remover is used for this, a slightly acidic, water-based liquid with oxidising power (usually from hydrogen peroxide).

Some chemicals have more than one use and suede oil is a good example. It not only preserves the colour, handle and texture of a suede but also allows a cleaner to restore the handle and “scrunch” of a silk fabric has lost its ”body” during drycleaning.

Grime left on jacket collar

Fault: After cleaning, the slight marking around the inside of this pink jacket’s collar had darkened and looked worse than before.

Cause: The original grime on the outside and inside of the collar was caused by normal contact with the wearer’s hair and skin. This resulted in mark-off of hair oils and skin sebum. These are water-based proteins and will come away in drycleaning if a pre-treatment detergent is used to provide localised moisture to soften the contamination. The surfactant in the pre-treatment detergent then makes the soiling soluble in the drycleaning solvent. If the collar grime is not correctly pre-treated then the proteins will not dissolve in the solvent wash and the tumble dry stage will darken them and set them onto the fabric.

Responsibility: The user is responsible for getting the soiling onto the garment. The cleaner is responsible for failing to pre-treat it adequately, if it darkens instead of coming clean.

Rectification: This is not usually possible. Sometimes a vigorous tamping with pre-treatment detergent and water in the ratio of the three parts detergent to one part water will improve the result but the chances are not good.

Defeated by cream stain

Fault: Spilt pouring cream left a stain on this jacket. The cleaner first tried machine drycleaning and then used protein remover without success.

Cause: The mistake was to try machine drycleaning first. Pouring cream contains fatty proteins, which do not dissolve in any drycleaning solvent. During drying, these oxidise with the heat and oxygen from the drying air stream. The resultant set protein is as difficult to remove from a fabric as a fried egg-white is from an unprotected frying pan.

Responsibility: Although the wearer is responsible for the original spill, the cleaner is directly responsible for failing to treat it correctly in the first place and for the stain becoming irremovable.

Rectification: The fault is usually irreversible but it is always worth trying to correct it, using an O.880 ammonia solution with appropriate pre-testing.

Removing red wine marks

Fault: This beige jacket was splashed by red wine at a party. Drycleaning it four times only made the marks fade slightly.

Cause: Machine drycleaning alone will never remove red wine stains, as the cleaner found. The red colour comes from the vegetable dye tannin, which must be bleached colourless.

Responsibility: While the owner is responsible for the original staining, the cleaner failed to treat it correctly, with either a proprietary tannin remover or hydrogen peroxide acidified with a little acetic acid.

Rectification: It is possible to remove red wine marking, even after four drycleans, provided that the sugars in the wine are first removed using warm water or steam. Once done, the red marks can be swiftly de-coloured. The stain can usually be removed completely from a pure white fabric but caution is needed with a coloured or pastel garment.

Silk becomes limp and faded

Fault: When this fine silk went into the perc drycleaning machine, it had a rich deep coloured print and felt luxurious and full bodied but after cleaning it was limp and looked faded.

Cause: Silk yarns are finished with yarn oils to give the fabric a high sheen and aid weaving speed. These oils also confer a full-bodied handle. However perc often dissolves these oils with the result described here.

Responsibility: It is essential to add machine detergent to any drycleaning machine load and in the case of silk, the detergent needs to be one designed to replace the silk oils and to maintain the body and handle. The responsibility for this vital step lies with the drycleaner.

Rectification: Silks spoilt this way can usually be restored to their original condition by re-cleaning using a detergent of the type described, correctly dosed. There will still be some loss of colour but the correct silk detergent will enhance the remaining colour to minimise any apparent fading.

Purple dress turns grey

Fault: This purple dress was drycleaned in pure distilled perc solvent. When it came out of the machine, the customer saw that the fabric looked grey and when she tried it on it clung and was unpleasant to wear.

Cause: The symptoms indicate that the drycleaning system used only pure solvent, with no charge of machine detergent. As a result the removed soiling was not held in suspension during the solvent wash and so the soiling was re-deposited on the purple fabric, causing overall greying. As there was no detergent to condition the fabric, a static charge was created whenever the fabric brushed against itself or another surface.

Responsibility: The cleaner is responsible for preventing re-deposition of soiling and creation of static, by failing to add sufficient machine detergent to the load being cleaned to prevent the faults found here.

Rectification: Re-cleaning the garment with the correct detergent charge should cure the static problem but the greying is irreversible.