Yes, more than 1mm...on the reverse of a buffalo nickel, the buffalo protrudes well above the field surface, so you can cut deeper from the front side in those areas, just have to be careful not to dig too deep into areas from the front opposite the lower field areas on the reverse, if that makes sense. It is also possible to push the metal, on the Indian face front, rather than just cut it away, providing more metal to shape. It doesn’t take much at this scale to create depth with raised surfaces. I also added scrap metal overlay from another nickel to raise low areas...the inner face of the Minotaur from forehead, cheeks, and chin; the tip of the club; right leg and hoof; and the rock that hoof rests upon, are all added metal. Inside of the cave is finely stippled with dark toning added to create a sense of depth as well.