First of all, Im new to leather working. Been doing smaller things for a year or so. Recently i have interested myself into dying and finishes. Ive been trying out various spirit based dyes and right now my favorite is the Fiebings Professional Oil Dye. I get great results with this dye and it penetrates the leather well. However i recently acquired a natural colored leather side 1,5mm thickness. It seems to have a light finish applied to it. Ive tried to dye this leather but the color only penetrates a very little amount. By very little i mean that a nail scratch penetrates the color and the natural color is exposed. Ive tried removing the finish with both denatured alcohol and aceton, same result. Ive even tried sanded the leather with 240 grit still bad color penetrating. So obviously something is stopping the dye to soak in. Could the fibers on top be compressed in anyway? I want to learn why it is behaving this way regardless if it can be fixed or not.
Ive tried dip dying still bad results.
Color penetrates flesh side very well but stops when reaching "grain side layer"
Appriciate any help!