Trophy/Display Backer

thingiverse

I've used it to back up this display item, which turned out fantastic: https://www.thingiverse.com/thing:145237. This backing works with just about any print setting, but a low infill of around 10% gets the job done nicely. Since it's a quick print, you can go all in on infill if you want to - it took only about 40 minutes and looked great.