Which laser for laser cutting

Robin2:

Grumpy_Mike:
I guess the safest thing, and not too complicated, is to operate the laser inside a box and use a camera (e.g. a webcam) to observe what is happening.

...R

if you have a CNC motorized unit, you do not have to watch.

I thought that many plastics would be 100% safe, same as laser rated glasses. if that is the case, you only need to have such a shield to protect yourself.