Rick is on it as always. Not a requirement just makes the job look 'finished' & professional. I as well usually recommended a vinyl swatch but in some situations you just know busy fingers are going to eventually do some damage & a simple metal oraluminum panel can be a quick easy solution.
I've also had opportunities that have allowed me to upsell jobs considerably because of this. For example a large state office building with hundreds of small offices which all had glass windows floor to ceiling on both sides of the door.
in this particular case the state originally called for the required room identification but to make it look 'planned' on the opposing side of the door we worked with the architect & co-created a same sized sliding 'message' system & then on the backside (inside the offices) we placed two equidistant brushed black anodized mixed medium panels with the state agency's logo on each. It was a great looking 'solution' that more than quadrupled the original approved work request..caching
but evenon a small scale I've found it to be an easy upsell to suggest an aluminum backer with a company logo, company 'core values' (sigh) & even custom made picture frames.
a great way to add a few bucks to a project while also improving the finished look,especially in high end or architectural settings where they are often less than 'happy' about having to invest to comply,gives 'designers' & architects a way to spend more client's money & sometimes enhance the building decor.