Photo transfer is great for capturing details in images. For example, it picks up subtle brush or pencil strokes in images of artwork. This techniques works with both black and white photos or ones in color. Photo transfer is only appropriate for certain types of leathers otherwise the transfer can crack. Vegetable tanned leather is a particularly nice canvas for photo transfers.
Silkscreening also captures detailed images. I generally use this technique in large production runs because it can be a very time consuming and finicky process. Silkscreening works best on vegetable tanned leather.
Stenciling can create crisp, clean lines, shapes, and outlines. All types of leather can be stenciled.