This recipe is based on "Dark Brown Leather" by RookieBrushes, so full credit to that author. My version follows the same instructions as RookieBrushes but uses an alternative set of paints I happened to already own.
  - Basecoat with   Burnt Umber  
 - Add   Royal Purple Shade  into any deep recesses
 - Glaze most of leather with   Mournfang Brown  drag towards edge to create texture
 - Use   Red Leather  for chunky edge highlight
 - Add thinner edge highlight of   Red Leather  and   Nurgling Green . Also use for scratches
 - Use   Nurgling Green  for corners and middle of large scratches
 - Add   White  to   Nurgling Green  at 1:1 dot apply to corners