Engraving for jewellery rolling mill

My girlfriend told me about how they put their silver through a rolling press with various items, at her jewellery class. So, I face machined a piece of 1.5mm steel sheet and engraved some mirrored designs on it. She took it to her jewellery class with some soft aluminium that I gave her and put them though the rolling mill. In the picture is the aluminium with the pattern pressed on to it. I think most of the pattern was too deep and has rough edges, but the shallower hexagon patterns were better.
The steel comes out bent, but you can use it many times.