YooHyuk

Hi, I was wondering if it was possible to use Ammonium Chloride and a stamp (stencil or hand drawing) in order to create a maker's mark. I've seen this technique used in wood working. You mix Ammonium Chloride with water and apply it to the wood using a stamp or using a felt pen and drawing your mark. Then you would take a heat gun to heat it up and through a chemical reaction, the solution would burn into the wood and the mark would appear. I'm wondering if this is also possible with leather.

I'm new to leatherworking and at times I accidentally get a small amount of guar gum or tokonole on the top side of the leather. It affects how much dye or oil is absorbed. What can I do to clean the leather? And what is the best method of keeping the top side clean in order to prevent unwanted residue or scuff mark?