The leather prep is used to remove the manufactured finish from leather. It also removes an solvent soluble waxes, oils & silicones, which unless removed could cause adhesion problems when colouring at later stages.
The main use of the Leather Prep is to remove old, worn and hardened coatings on leather. These are the original Colours and Finishes applied to the leather in the tannery, that over the years harden and become unsightly. Often, when leather is cracked, it isn’t actually the leather that has cracked, but the coatings sitting on the leather.
Using the Leather Prep and an Abrasive Pad to remove the manufactured coating, therefore removes the cracking, making the leather look much better & feel a great deal softer.
The leather can now be sanded smooth and any damage to the leather can be repaired. Removing the old coatings make for a much better end result, not only in terms of appearance, but also for touch & comfort when used.
If the leather is old, and you want to remove the manufactured finish (as indicated in the above photos), then the best way to prep the leather is with an Abrasive Pad. Wet the leather with the Prep and rub with the pad, the Prep will start to emulsify the old coating and the pad will loosen it. Wet a cloth with the prep and/or spray some prep onto the leather and wipe over with the cloth. This will remove any excess colour/finish still on the leather.
If the leather isn’t badly damaged it doesn’t require such drastic action. The leather can be simply wiped down with a cloth dampened in prep.
In both cases though, you should expect to see colour transferred onto the cloth, indicating the Prep is working.
You can see that in this example of leather that has been prepped, that the prep hasn’t removed much colour, but it has greatly cleaned the leather and also removed the creases and cracks. This is because the majority of the damage on the leather is in the painted layer, and so when we prep the leather, we reduce the painted layer and so soften and smooth the leather.