What is the use of photo tool in Photochemical milling process?

What is the use of photo tool in Photochemical milling process? Correct Answer Protection of surface against etching

In PCM, photo tool is applied as coating which act as stencil resist that protect the surface from etching.

Related Questions

What is the similarity between normal Chemical milling process and Photo chemical milling?
The question below consists of a question and two statements numbered I and II given below it. You have to decide whether the data provided in which of the statements are sufficient to answer the question. Choose your answer from the options based on this. What is the code of “Actor”?
I. In a certain language, “road trip wine” is written as “bk mk tk” and “wine actor photo” is written as “gk rk bk”.
II. In a certain language, “photo wine cycle” is written as “bk ak rk” and “cycle actor photo” is written as “gk ak rk”.