The word "backdrop" refers to the background or setting against which something happens or takes place. It is the scenery or environment that provides context and makes something stand out. Full definition
Though sometimes I will begin a painting with a kind of backdrop of stripes. (huntedprojects.com)
Use these as backdrop for your existing plates, whether you're using ceramic or paper plates, give them a festive look by placing them on top of these charger plates. (trendmebeauty.ca)
It was this point that led me to use it as backdrop for a story. (bookbrowse.com)