Carve a signature in it. If it is a finished product, it seems that you can only cut the crystal. It was carved with a laser marking machine or engraving machine and then closed, but it can be seen even if it is well combined. If you are afraid that engraving your signature on the outside will drop or fail, you can use a laser marking machine, and the effect is just as good.

You can go to the place where the seal is engraved or the place where the billboard is made. Generally, the above equipment is available, and the price is not expensive.

I hope my answer is helpful to you. If I don't understand anything, I'll do it.