Cmac;
I should have asked you what you were dying with leather dye. I was thinking wood, because so many builders use leather dye for that purpose. For leather, the majority of the products leather companies sell is some kind if acrylic clear. Which means artists clear acrylic in gloss or matte will work, but the acrylic clear floor finishes will work as well. You will get a very unnatural shine from the gloss acrylic coatings. If you want an aged look use the artists acrylic clear in semi-gloss. This stuff can be mixed with water, chalk line chalk, and, or masonry tinting powder, to achieve the look of native American paint on wood, rawhide, skulls, or leather.
Hungry Horse