How to clean and maintain leather car seats (Detailed)

On closer examination, it is clear to see that the cleaning and caring of car leather is a little more complex than just picking up and applying any cleaner or conditioner. Leather professionals, detailers and car enthusiasts usually ask us questions like “What leather do I have?”, “What is the best way to look after my leather?”, “Does the product that prevents dye transfer also condition the leather?” and many more. We have put together the following information with the aim of answering most of these common questions.

BASIC KNOWLEDGE OF AUTOMOTIVE LEATHER

The use of leather in vehicles dates back to well before the first car was even built. Before the existence of our modern car, leather was used in horse carriages.

Mercedes 300D Adenauer built in 1958.

Lamborghini Espada built in 1970.

Lancia Astura 4th Series Pinin Farina Cabriolet built in 1939.

Besides the seats, leather was used for bonnet straps, belts, door panels, steering wheels and dashboards.

Braided Leather Handle Mercedes

Leather cuff and carpet edging

Bonnet Strap

The tanning process irreversibly preserves animal skins by turning them into leather. Leather is made of intertwined collagen fibres, consisting of protein, which together form a stable and tear-resistant material. Depending on the type of skin and tanning process, leather contains 45-75% skin substance (collagen fibres), 8-45% tannins, 1-25% fat, 3% dyes and pigments, and 8-15% moisture. The tannins prevent the disintegration of the leather, and the moisture and fat make the leather supple.

The tanning drum

Tannins: quebracho, chromium (III), synthetic tanning

Structure of the leather fibres: fine and tear proof

Leather is available from various animal species and in many forms. Since the dawn of motorised vehicles, the skin of cattle has been the preferred material to cover seats and other components of the vehicle. Cowhides have large surfaces and are also extremely robust. They can easily be dyed, embossed and stitched. It is a noble, natural and breathable commodity.

Exotic examples of car leathers: Ostrich leather in Bugatti, cowhide in BMW, iguana leather in Mercedes.

Traditionally, leather interiors were installed only in the more valuable vehicles. However, the use of leather in car interiors has increased steadily and continues to do so today. Medium-priced vehicles are now equipped with leather upholstery. Classic cars which didn’t have leather interiors are now exhibited at antique car shows with leather upholstery. It would be fair to say that vehicles with leather interiors have always had a noble aura and therefore a higher resale value.

Gullwing: Original in fabric

Nowadays almost exclusively in leather

Beetle convertible upholstered in black with red piping

Car leathers are 99.9% pigmented leather. This is leather with a colour layer sealing the surface. Vegetable tanning was the only tanning process known to mankind until, in recent decades, chrome-tanning and synthetic tanning methods had been developed. These new tanning methods are cheaper, less time-consuming and produce softer leathers. When cleaning and maintaining leather, the kind of tanning is not critical, but identifying the age and condition of the leather is highly important.

THE SELECTION OF CLEANERS AND MAINTENANCE PRODUCTS, AUTOMOTIVE LEATHER

There are a wide range of products available for the cleaning and care of leather. These are widely offered by car care suppliers who have a full range of car care products and usually have a leather cleaner and care product in their catalogue. By contrast, leather-specialised companies often have several products for various leather types and conditions. This raises the question whether one type of leather conditioner is enough to maintain the beauty of new leather, or to keep the beautiful patina of old leather for as long as possible.

Leather can be new or antique, matt or gloss, perforated or embossed or with decorative seams. Some leathers show heavy soiling as they are barn finds. These might be hard, dry and cracked. Others are perfectly clean and maintained.

IS LEATHER CARE AND CLEANING IMPORTANT?

Unfortunately for us, no one is legally obliged to do so, but it is important to regularly maintain leather to ensure the longevity of leather interiors. Dirt and dust make the surface dull over time. Grease stains and colour damage often occurs on steering wheels, gear knobs and handles covered in leather. Not to mention that it makes total sense from a hygiene perspective to clean it occasionally.

Leather is also made of fats & oils which maintain its suppleness. The appropriate care products will ensure adequate rehydration so the leather does not become dry and brittle, they will make the surface smooth, which in turn reduces the signs of wear.

ARE THERE GOOD AND BAD CLEANING AND CARE PRODUCTS FOR LEATHER?

Due to the large selection of manufacturers, there is often uncertainty as to what is the right product, and whether cleaning and care products can possibly cause damage. Cleaning and care products have been tested often in the recent decades, however, the results are varied depending on the parameters of these tests and the condition of the leather. This may have contributed to an increase in the uncertainty.

A key error in the cleaning and maintenance of leathers is the use of unsuitable products. A Wheel Cleaner certainly makes soiled leather clean and spotless. But such cleaners are very alkaline and harm leather in the long term. Care products such as body lotions are also not optimal for preservation. A living skin has different needs than tanned animal hide, and perishable fats and oils oxidise (become rancid) and damage the leather, not to mention the hygiene factor.

It is very rare to have products supplied by a reputed company inflict any damage to leather. While there are differences in quality, a typical automotive leather in good condition is compatible with all commercially available agents. Providers of high quality leather care often invest more in the optimal formula and ingredients in comparison to the cheaper providers who only pay attention to basic protection. All that aside, the worst care is not to care at all.

WHAT IS THE BEST CARE FOR CAR LEATHER?

Use it carefully! Whilst leather is extremely robust and durable, leaving it permanently in the midday sun with the top down will cause the colour to fade and the leather to become dry and brittle over time. With careful treatment and regular but not excessive cleaning and maintenance, leather will last a very long time.

WHAT SHOULD BE CONSIDERED WHEN CLEANING VEHICLE LEATHERS?

• If the type of leather is unknown, we recommend carrying out a small test. Rub a drop of water in a hidden area to see if it penetrates the surface. Almost all automotive leather is protected by a layer of paint/pigment, but some are porous (aniline leather, suede & nubuck). Porous leathers are very sensitive to water. Any water-based cleaners can cause a stain which cannot easily be removed. If water penetrates the surface, always ask a specialist for help. If water does not penetrate the surface, the leather can be easily cleaned with water-based cleaners.

Protective layer of paint: water runs off

Porous leather: water penetrates and leaves stains

Porous leather in vintage car - not easily recognizable

• Does leather need to be cleaned when it looks clean? This is easy to test. Take some cleaner on a bright-coloured cleaning cloth and gently wipe the seat. If any soiling is visible on the cloth, a more thorough cleaning is necessary. If the cloth is clean, no special effort is necessary. This applies to all surfaces in the vehicle.
• Leather should not be cleaned too wet. Even if almost all automotive leather has a protective coat of paint, older leather is often brittle leaving certain areas porous. Hence, it is important to not soak them with cleaners. They should be cleaned using a foam cleaner. Any product residues can be removed with a slightly damp cloth.
• Do I need a cleaning brush? Leather usually has a recognisable grain structure and dirt collects in the graining and recesses. If a cloth or sponge is used, then you have to press down very firmly and rub to loosen the dirt. In such cases, a cleaning brush is a great help and a very handy tool. All brushes that are not harsh on your own skin, can be used. Wire brushes and scouring pads are not a good idea!

Soiled cloth? Cleaning is necessary

Dirt in the grain? Use the brush

For barn finds, use a stronger cleaner

• Cloth or sponge? It is best to use a sponge to clean smooth surface areas and a cleaning brush to get into the graining. Remove all cleaning residues with a damp cloth. Always use a bright cloth, so you can see the degree of contamination. To maintain, a soft cloth (such as a towel) is the best choice. Microfibre cloths are also good, but have a slightly abrasive effect which could cause damage only when cleaned intensively. But since there are enough alternatives, we always recommend using a softer cloth.
• When cleaning and applying any care product, always work in circular motions and work from seam to seam. This prevents any wipe marks.
• Mild Leather Cleaner or Strong Leather Cleaner? If the leather is very dirty, then the Strong Leather Cleaner should be used in conjunction with the cleaning brush. If it is just a routine cleaning with barely visible stains, then the Mild Leather Cleaner with a soft cloth or sponge should suffice.
• Why can’t I always use the Strong Cleaner? The golden rule for all cleaning applications: The gentlest cleaning agent is also the gentlest option. If leather is not very dirty, a gentle yet effective cleaner is always best choice. Stronger cleaners may not be necessary and are also not the best in the long term.
• If a simple cleaning is not enough, what stronger agents may be used? Commercially available leather cleaners are water-based and water-soluble. Contaminants should be easily removable using these. When cleaning adhesive residues and greasy soiling, COLOURLOCK Cleaning Spirit can also be used. When abrasion caused by shoe soles appears at the edges of the seats and door panels, a transparent eraser is a useful tool. Always test first in a hidden area for any changes.
• When cleaning ink and dye stains, it is always better to contact us. A short email with a couple of photos of the damage will allow us to give you the best advice and recommend appropriate products. Sharper solvents dissolve most of the ink layer of the leather and should be used only in extreme cases and after consultation with a specialist.

Real barn finds: Brush and a strong cleaner

Many leathers look as good as new after cleaning

Dye stains. A specialist is needed

• I cannot remove dirt from the folds and side bolster or stains remain despite cleaning - In the entry and exit areas of the driver's seat, leather is often scuffed, small cracks appear or the colour is worn. For someone who does not have much experience, it is easy to assume this is dirt or stains. Any cleaning attempts with a wet cleaner only make the leather darker as it absorbs moisture. On drying, the areas light up again and remain visible, but such colour damage can only be restored using a leather dye.

The colour is rubbed off: A colour restoration is necessary

Breaks and no dirt: The brush cannot help

If the damage is not too big: A colour restoration is most suitable

• Fresh stains and contaminants should always be removed immediately. Especially dye transfer stains (from jeans and other clothing) should be removed as soon as possible. If not treated immediately, they can penetrate the surface of the leather after which they are no longer easy to remove without professional help.
• What precautions should I take when cleaning stitches and seams? In particular, different-coloured seams and embroidery can get contaminated when cleaning. If the leather is particularly dirty, the areas away from the seam should always be cleaned first. Care must be taken that dirt is not wiped onto the stitching. Contaminated seams and embroideries can then be cleaned only with textile cleaners. However, it is usually not possible to fully clean them if they become soiled or discoloured.

• What precautions should I take when cleaning perforated and embossed leather? Perforations are holes punched out of the leather, as opposed to imprints which are pressed into the leather structure. When dealing with perforated leather, you should make sure that the leather doesn’t become too wet during cleaning and maintenance, as fluids will easily pass through the perforations in the leather and sit in the cushioning material behind it. This can cause the edges to swell and stains can appear. But this will only occur if you are extremely careless. Embossing provides a stronger structure to the leather surface. Care should be taken when applying a leather conditioner so as to not fill the holes. Excess application of leather creams or leather milk can cause whitish stains. The same applies to leather fats or waxes. If too much is applied, the excess must be heavily polished or cleaned away. Rubbing some of the product into a soft cloth to apply it can therefore save a lot of time and work. Also, start by treating areas of the leather which are not perforated or embossed in order to avoid overdosing.

Perforation and embossing: Clean and maintain sparingly

Perforated leather when treated too wet

Mould due to incorrect storage

• What if there is mould on the leather? Leather with mould should be cleaned immediately and wiped with diluted vinegar. If you act quickly on white mould, the problem is very easily solved. However, if you have black mould, there is no way of cleaning it and if the smell has gone deep into the cushioning material, you might get the leather looking clean, but the smell will linger unless you can trace the source of the smell and treat it with odour removal sprays. Important! In the future, avoid high humidity without air circulation inside the vehicle. Otherwise the problem will return straight away.

WHAT SHOULD BE CONSIDERED IN LEATHER CARE?

There are a variety of leather conditions and leather care products. Most cleaners can be tested by eye as the results are visible straight away. However, this is not the case with care products or conditioners. The effectiveness of the product can only be judged over time. Although, most good quality conditioners should make the leather feel softer shortly after application.

• How do I know the need for care? New cars or classic cars in which the leather upholstery has been re-trimmed have brand-new leather.
• New leather usually does not require any special maintenance, since the tanner did his best possible. But light-coloured or bright-coloured leathers tend to get affected by dye transfer stains. Frequently used vehicles are prone to wear and tear like scuffs and colour damage. Applying COLOURLOCK Leather Shield drastically reduces this and ensures the leather stays as new for as long as possible. The only care or protection new leather needs is against these problems and only in the contact areas.

Old leather in top condition: Austin Healey 100M BN1 built in 1954, Bentley built in 1938, Rolls Royce Corniche II built in 1983.

In older leather you have to look more closely. Old leather in good condition should be maintained every 6 to 12 months in order to maintain its condition. If a leather is stiff, dull and feels dry, it is mostly due to a lack of conditioner. There is no unique criterion, but if you touch the leather of various vehicles and compare, you quickly get a sense of which condition the leather is in.

Clearly in need of care: Old, dry and wear.

• Pressure tests are used to identify whether the leather is dry by seeing if there are wrinkles on leather. However, this is not always conclusive and not always correct. The fibre structure of the leather is very different within a raw hide. The centre of the skin has a denser structure than the edges. Therefore, the way the leather folds and wraps can vary even on a single surface. For this reason, the pressure test is not enough, and this type of wrinkle formation cannot be mitigated by use of care products.

Headrest pressure test reveals no wrinkles in the middle

However in corners, the leather wrinkles significantly

Leather cross-section: left loose thin fibre structure, right dense fibres

• How do I care for older leather? Classic leather care products range from leather grease, leather oil, leather balm or leather milk. Oils and fats are pure products and therefore highly moisturising. For normal care, such products are excessive. A balm or care milk are emulsions with water. COLOURLOCK Leather Protector contains oils that are sufficient to keep the vehicle leather supple. The Leather Protector is thin and therefore penetrates very well into the leather. The COLOURLOCK Elephant Leather Preserver protects the surface more as well as helping soften the leather and waterproofing it. The COLOURLOCK Leather Protector is designed for matt leather. The COLOURLOCK Elephant Leather Preserver gives a glossy finish. In particular, very old leather of classic cars tends to be shiny and very dry. In such cases, it makes sense to combine the products. First, apply the Leather Protector and let it penetrate into the leather, followed by the protective leather wax to match the degree of gloss. COLOURLOCK Elephant Leather Preserver should be used excessively only on very dry leathers. Otherwise, use both products sparingly. For extreme cases of dry leather, use COLOURLOCK Leather Softener for a one-off treatment.

 

 

Shiny leather (middle metallic effect)

• I would like my leather to have a matt finish but certain areas are too shiny or glossy. New and modern car leathers have a matt finish. Certain older cars also have matt finished leather. The more the leather is polished or buffed, the shinier it becomes. In particular, the driver’s seat and the steering wheel can become shiny or greasy. When matt leather is viewed under a microscope, it appears to be a rougher surface. The way the light reflects on a rough surface is what causes the matt look. In contrast, light reflects in a parallel direction from glossy leather, giving it a shinier appearance. Over time, if a leather becomes greasy and polished, it loses the roughness and thereby also its matt appearance. To keep a leather matt, it should be thoroughly cleaned and maintained, but under no circumstances with strong oiling or greasing products. COLOURLOCK Leather Protector is the most suitable product within our range for matt leather. When applying the protector, ensure you do not buff or polish the leather. Apply the product by working from seam to seam and allow it to dry. Residues from any cleaners should be wiped gently with a slightly damp cloth. Additionally, COLOURLOCK Gloss Correctors can also help with adjusting gloss levels. However, we always recommend the following steps:

STEP 1 - Clean thoroughly and apply Leather Protector (do not buff or polish)
STEP 2 - Clean, degrease with COLOURLOCK Cleaning Spirit & then apply Leather Protector (do not buff or polish)
STEP 3 - If the above 2 do not work, apply COLOURLOCK Gloss Corrector. When working on an area with a large surface, it is best to spray the gloss corrector using an airbrush.

Left and middle rough, matt new leather, right smooth leather with more shine.

• Does car leather have UV protection? Over time, sunlight affects all materials. Whether it is the car paint, the hood or the leather interior. Therefore, the best protection is to permanently avoid intense sunlight. UV rays cause the leather colour to fade, and the warmth of the sun heats up the leather and makes it age faster. In the worst cases, it can even shrink the leather, leading to irreparable damage. The UV protection in the COLOURLOCK Leather Protector is not a must-have, but it provides additional protection.

Not too common, but occurs occasionally: fading

Permanent sunlight harms leather

BMW E30 convertible. Shrunken leather in the rear seat

• How often and how much should leather be maintained? Car leather is usually not maintained often enough. For cars where the leather is in good condition and only used seasonally, it is recommended to care every 6-12 months. If the car is used regularly, at least the driver's seat should be maintained more often. However, applying excessive amounts of car e products or applying them too often can make it greasy and oily. The ideal way to treat leather is using less product, but frequently. Contact areas with hands (steering wheel, armrests, handles, etc.) should sparingly be maintained with care products. Regular contact softens the colour layers over time and use of excessive care product can speed up this process. Applying COLOURLOCK Leather Shield to areas which are already slightly damaged is best as it is a sealant which reduces friction damage.
• What do you do when dealing with hardened leathers? Leather that has become hard by age but not shrunken because of heat or sunlight can be treated using COLOURLOCK Leather Softener. This product contains very low-viscosity oils that need to be applied patiently. Apply the product and knead the leather. This helps to loosen the fibres. Please contact us if you are facing a similar situation, as hardened leather needs to be treated differently if it has a lot of scratches to be repaired or needs to be coloured.

Aging has made the leather hard - it can be softened again with products and by kneading the leather.

• Do leather care products really penetrate the colour surface? Unlike synthetic leathers, surface-coloured car leathers have more breathability. This allows care products to sink into the leather. Care products penetrate better into damaged or older leather. In fact, the older the better. New or well-preserved leather does not need care to improve its condition. However, it needs surface protection like the one provided by COLOURLOCK Leather Shield. If the car is older than 3 years, either COLOURLOCK Leather Protector or a combination of both Protector & Shield can be used for optimal protection.
• Which product should I apply first? Always clean first. If the Leather Shield is applied in combination with the Leather Protector, the following procedure is the best: First, apply the Leather Protector. Take some Protector in a soft cloth, and apply gently. You don’t need to polish the leather. Visible excess product can be removed with a cloth dampened with water. Wait a few days before applying the Leather Shield. This way, you allow the leather to absorb the oils in the Protector which will keep it soft and supple. A week is optimal as the products need time to penetrate through the top ink layer. The Shield prevents wear, scuffs and dye transfer and therefore must be applied only in areas of contact. This includes steering wheels, door handles and leather gear knobs. Backs of front seats and trim parts in unstressed areas can be left out. Take some Leather Shield in a cloth and apply thinly working from seam to seam. Then let it dry by itself without polishing. If you cannot allow much drying time, you should reverse the order. First, apply the Shield and dry with a hair dryer. Then apply the Protector and do not polish. The Protector will eventually penetrate through the Leather Shield. If the Leather Shield is applied directly on the Leather Protector, it will not stay on the lightly oiled surface as the Protector takes time to penetrate the leather. If the Leather Protector is used in combination with the Elephant Leather Preserver wax, first apply the Protector as it is a thinner product and feeds the leather well. Following this, the surface can be protected by using the Leather Preserver.
• How long should you wait between steps? Allow the leather to dry after cleaning. You can speed up the drying process by using a hairdryer or heat gun. Ensure the air is not too hot. When applying a combination of products, always allow the first product to completely dry before applying the next one.
• How long do you have to wait until you can sit in the car again? Leather care products should always be used sparingly but regularly. After a light application, the care products are absorbed fast and dry quickly. Once that is done, you can strain the surfaces again. In pleasant temperatures, it should take less than 15 minutes. On cold days, you should wait a little longer, as it will take longer for the leather to dry.
• Does the working temperature matter? Yes! It is recommended to clean and maintain the leather only on warm days or in a heated garage. Let’s face it… cleaning is not fun on a cold day, but more importantly it is not advisable to dry the leather in very cold weather. Also, working on a cold day would mean the doors in the car will be shut not long after cleaning. This means there is a risk that residual moisture stays inside the car which in the long term can encourage mould formation. However, it should not be done under any circumstances in the blazing sunshine. Slightly moist leather can be damaged immediately by direct sunlight.

• How important is it to waterproof leather? A leather waterproofing product is only used to make surfaces water-repellent and has no emollients (agents that soften the leather). Car leather needs moisturising to stay supple, but any liquids or water that come into contact with car leather do not penetrate through the protective layer of paint. A hydrophobic product or waterproofing spray is therefore more suitable for shoes, motorcycle suits and perhaps convertibles or cabriolets because they are directly exposed to the weather. It is not very logical to test the waterproofing properties of care products on car leather. Unlike sensitive aniline leather (suede & nubuck), factors that damage pigmented leather are not influenced by liquids penetrating the leather. In fact, you want the care products to penetrate to ensure the oils reach the fibres. Therefore, any water repellent product for car leather is actually counterproductive. Leather waxes have a waterproofing effect and melt when hot, eventually penetrating the leather.
• Can pressure marks, wrinkles and bumps on leather be removed with care products? Wrinkles and bumps are usually a natural process of change in the ageing of leather. As long as it is not a clear crack or scuff, they are part of the leather. Wrinkles and bumps cannot be repaired using care products. If the fibre structure of the leather is permanently overstretched by use in these areas, it will not stiffen or revert back to its original condition again. In case of pressure marks, re-oiling and loosening the fibres using a hairdryer and massaging the leather can have a positive effect and reduce the signs. It is also important to note how long and how heavily the pressure was applied to it.

Wrinkles on leather: They belong to the leather

Pressure marks on leather: Can be improved

Dents in leather: Will need re-trimming

• Can new car leather smell be recovered by regular care? Due to the current tanning methods, modern leather no longer has that beautiful smell of old vegetable-tanned leather. But most smells and odours evaporate over time. If leather is maintained, this will ensure it stays for longer. However, anyone wishing to re-introduce the leather smell can try COLOURLOCK Leather Essence. It comes with a patch of vegetable-tanned leather to leave inside the car. The more product applied and warmer the temperature inside the car, the more intense the smell.
• What to look for when the vehicle is stored for an extended period? Vehicle leather is actually a very economical material that does not get easily damaged. It may be damaged in extreme conditions if stored for a long period. Extremely dry air would make the leather dry. Therefore, a humidity of 50-70% with sufficient air circulation is optimal. In the absence of airflow, 70% humidity is enough to start the formation of mould. Ventilate the car by opening the window slightly if humidity levels are quite high. If humidity is low, maintain in shorter intervals. In any case, it always makes sense to regularly inspect the condition of a vehicle. Is there enough air in the tires? Does it smell of mould? The optimum storage temperature for leather is 15-20°C. But permanently lower temperature is not bad! Leather suffers more when subjected to constant changes in humidity and temperature or to permanent sunlight. Constant use and visual inspections plus an occasional maintenance treatment are the best methods of conservation. Keeping heavy items on leather leads to pressure marks. If kept in contact with leather for a long time, they can become permanent.
• Leatherette, Faux leather, Vinyl or Artificial leather, also known as imitation leather, or even plastic parts are often indistinguishable from genuine leathers, and both materials are often combined in a vehicle interior. Do normal leather care products harm Leatherette? When cleaning, it does not matter whether one uses the leather cleaner on real leather or vinyl. Since leather is the more sensitive material of the two, other materials are not damaged. Not every leatherette or any plastic can withstand permanent and intensive greasing. Unlike leather, oils and fats cannot soften vinyl or plastics. Although occasional care does not cause any harm, it is best not to apply leather care products on hardened artificial leathers or synthetic materials.
• Do care products change the patina of leather? Patina refers to a change in a material due to ageing, but this is seen as an embellishment and not as damage. Modern leather is heavily dyed, and due to abrasion and wear a similar but slightly faded colour appears in the damaged area. These visible marks are not seen as patina but as damage. On the other hand, vegetable-tanned leathers used previously were not dyed, but just coloured on the surface. Over time and with use, the lighter natural colour gets revealed, leading to an age-based patina. It is common to find this type of leather in classic cars, where this isn’t seen as a flaw or damage. It only adds to the beauty of the leather.

Wonderful patina: Glossy and small wrinkles

In direct comparison: New leather lacks the patina

New leather re-trimmed in classic car: Leather looks artificial

On beige or light-coloured leather, dirt gets into the graining and in some cases can appear as patina. If the patina is caused by dirt and not wear, it can be removed by cleaning. Other existing patina can be preserved for much longer by regular cleaning and care.

Beautiful patina: Vegetable tanned leather

Aging beautifully despite signs of wear

New leather with traces lacks the appearance of a patina

CONCLUSION

While there are many points to be observed when cleaning and maintaining leather, the basic rules are simple. Regular cleaning and maintenance without heavy application of products is the best way to enjoy your leather interior for a long time. If there are any damages, always react quickly and get in touch with us.

Most problems occur because people react very late. Whilst leather interiors can always be replaced, vehicles with well-preserved original leather with patina will always be worth a lot more!

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