leather is a mesh of collegen fibers. The tensile strength of leather depends on how densely the fibers are packed and the thickness. If you take human skin which remains flexible and soft (when young) you will notice that there is a high percentage of fat and other substances between the collogen fibers which retains a certain level of moisture and plumpness (not strictly just water). This allows the flexing of the fibers which have resilience. When skin gets old and or dry the surface starts to flake off and there is a general loss of moisture and fat.  The fibers themselves are my prone to crack if bent and there is cutting friction between the fibers.

Allthough leather is not a living substance (and therefore does not replenish itself) the same mechanisms are at work within it. Bone dry fibers are not resilient and prone to breaking when bent. There is no lubrication to allow the fibers to move against each other on the whole mesh of substance is more prone to the infiltration of dust and dirt which in practical purpose act like abrasives increasing the cutting action when you flex the leather.  This is why that winter boots will often crack more easily because water has carried dirt and salt that form sharp crystals within the leather and cut the fibers more aggresively. This is also one of the reasons why tanneries (such as Weinheimer) suggest that leather be stored at a certain miminum humidity level (70*) and that the leather but specifically moistenned additionally when lasting occurs.


As such a competent shoe product must accomplish several tasks.
1) It must provide minimal lubrication/moisture to older leathers that have lost the original volatile content through time.
2) It must fill internal voids in order to prevent the lodging of forign matter and or displace foriegn abrasive matter
3) It must provide a resilient surface barrier that will flex with the leather that will prevent foreign matter from entering in the first place.

All of these tasks are not necessarily easy to achieve all at once. For instance acting as a surface barrier sounds easy but many waxes and finishes fail at this becasue they become too hard and brittle and can not flex with the leather and or lose adherancce to the leather - hence flake off.  The waxes wwithin the saphir products remain softer and more flexible in my experience than any other waxed I have used. The consequence of this is that they are not as good at achieving the mirror gloss and instead provide more of a glow and never flake off. (Hard substances are easy to become polished and soft ones less so.)

Saphir also has a significantly higher amount of substance that will penetrate the leather and provide greater moisture and lubrication. Its important to note that yes you could use body moisturisers but you would have to make sure that these do not just contain water absorbing molecules (many  do) and alos are not too greasy which will cause dirt to stick to the leather as well. A optimal balance is needed.

As a side note one of the finest body moisturisers is Body Shop's Hemp Body Butter and I suspect this would work well to moisture leather as it contains lots of shea butter, glycerin, cocoa seed butter which all resist going rancid very well and are not volatile.

Not respecting all of this doesn't mean your shoes will fall apart but that they will not neccesarily look and stay thier best. Just like human skin. How many guys do you know that have skin as nice as womens and especially women following very strict skin regimens.

edited for clarity

Last edited by xenon1 (2012-11-30 11:39:45)

Last edited by Sammy Ambrose (2012-12-03 10:35:50)