Hi BP,
Usually for a clear emboss, the strokes of your design or text should be AT LEAST 0.5mm. Although our CNC machines can be as precise as 0.3mm, we don't suggest our clients to go this small. Since different fonts have different size of strokes, it is not accurate to refer the min. type size for a clear emboss.
So how big is your stamp gonna be? You are welcome to send us the artwork to calvin@lwleathers.com and we can check if it will give a clear emboss on leathers.