Metal punch stamp: suitable for stamping aluminium, brass, copper, silver, gold and ect. (also fits for annealed steel and hot stamping on steel) The image should be sent before the purchase to make sure it is doable. The optional size of the stamp is 4-20mm. If you want it larger than 20mm, it needs to be custom made. If you want to customize the stamp, please upload high-resolution black and white (not grayscale and not colorful) logo in JPEG, PNG, AI, EPS, CDR, JDP or PDF format. Black areas of your logo will be raised on a stamp (black areas of Your logo will be pressed into the blank). Please note that solid patterns require professional stamping equipment to leave marks.