Summary

Remix of https://www.thingiverse.com/thing:6196452
I added larger through holes to allow a normal sized screwdriver to fit for mounting along with increasing the width to accommodate the larger holes. This takes a 7/8" dowel rod and there is embossed text on the back stating this.

UPDATE: I uploaded this file again as I may have had the wrong file without the larger holes. If you've already downloaded this, please use this version.

I have about 12kg of filament using only two brackets and it holds securely. (Studs are at 24" instead of 16" as they should be, using three brackets will definitely hold your filament rolls without issue).