Most leather used for automotive upholstery has a finish applied that comprises a polyurethane protective layer and an abrasion resistant topcoat.
Polyurethane is a polymer composed of a chain of organic units joined by Ethyl carbamate (urethane) links; the polyurethane used is categorized as an elastomers; it has elastic properties while maintaining some rigidity. It is semi-permeable and has micro pores that allow hydration (transpiration and evaporation of moisture); otherwise it would become less supple and the finish will be subject to cracking.
Leather is hygroscopic (naturally absorbs and retains water), meaning it’s also susceptible to losing the moisture necessary to keep it pliant and soft. The denaturing process of leather tanning removes moisture from the hide; water-based products restore the lost moisture of leather hides to maintain its natural flexibility
‘Cardboard hard (Finished or Unfinished) Leather
Is a certain indication that the leather has been allowed to dehydrate. The corium is packed with collagen protein fibres, arranged in larger bundles and interwoven to give the structure great strength, excellent elasticity and durability.
In the tanning process these fibres and impregnated with collagens and polymers that are designed to hold them together and keep them supple. Much of the suppleness of leather comes from its moisture content. After tanning the skin is protected with a thin pigmented (colour) urethane and then a clear topcoat.
When corium fibres lose moisture they shrink, when they are hydrated with water moisture they swell. The best way to care for finished leather and to keep wrinkles to a minimum is to keep the leather properly hydrated and avoid, as much as possible, these shrinking and swelling cycles. Keeping leather hydrated only requires a regular wipe down with a damp cotton towel.
To restore the suppleness to finished leather apply Leather Master™ Soft Touch to a clean surface - this is not a conditioner per se but is used to improve and maintain the tactile feel and lustre (Patina) by rehydration and to ensure the leather remains matte, soft and supple.
Apply a small amount to dry 100% cotton micro fibre towel, allow to dwell for 20-30 minutes and then wipe surface with a dry 100% cotton micro fibre towel. For revitalizing older leathers and also to improve the feel of stiff leathers it’s better to apply several thin layers than a heavy application
Ensure that the surface of the finished leather is clean and dust-free. Fill a fine mist atomizer spray bottle (Kwazar Mercury Pro) with distilled water; lightly mist the surface and then using a damp 100% cotton towel wipe the surface
I hope the above article was informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.
Questions and/ or constructive comments are always appreciated
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