Embossing & Engraving
Engraving and embossing can be incorporated into some designs.
Brass plaques are used for the engraving; the art/lettering once
engraved can be left natural or oxidised to give an old world look.
Brass plaques can also be black "print" style - called sublimation print.

Some leathers lend themselves to embossing better that others,
embossing can be in gold black or natural (clear) no colour
used at all, just the imprint into the leather.