How acid print image on metal by etching process?

Firstly, u have to choose a good metallic piece or a special stone piece. It is better if they are flat.

Then, use one special kind of plastic paper which includes 2 layers : paper and pastic to cut the image u want on its surface which is plastic side. To do that u have to use a computer connected with another machine, maybe it is called "computer knife"...

When u have the cut image, u peel the paper layer out if the plastic paper. Then, u will see an adhesive layer on the back of the plastic layer, this layer helps u stick the plastic sheet on the surface of metal or stone.

Next, u pick the pieces of cutting lines or shapes up, u see the pict.

Then,use a special kind of acid to spill over the piece of metal or stone. The acid immediately eats into the metal tracing the lines which are made before. After some seconds or minutes, use some water to wash all of the acid left. These eaten lines create the image u desire.