12 Do's and Don'ts for a Successful custom metal signs
https://tysonxrnv470.home.blog/2019/12/24/7-horrible-mistakes-youre-making-with-custom-metal-signs/
Perspex is one of these. Its light-weight and transparent kind of thermoplastic can resist breaking contrary to glass. So, it is a substitute for heavier, shatter-inclined glass.