Heavy duty steel L brackets. Made from 3/8" x 1-1/2" material with a load rating of 120 Ibs. per bracket. Two 1/4" holes for wall mounting and two 1/4" holes for shelf mounting. All brackets are unfinished. Sold as singles. Hardware not included. Designed and fabricated by ARMdesigns.
12" bracket- 11-1/4" shelf arm and 6" wall leg.
10" bracket- 9-1/4" shelf arm and 6" wall leg
8" bracket- 7-1/4" shelf arm and 4-1/2" wall leg
6" bracket- 5-1/2" shelf arm and 3-1/2" wall leg.
Heavy Duty L-Bracket
I have had good results using this paint.
https://www.rustoleum.com/product-catalog/consumer-brands/painters-touch-2x-ultra-cover/satin
You Can also wipe on Treewax Paste Wax if you want to keep the natural look. It dries hard with a clear matte finish. https://www.amazon.com/Trewax-Natural-Carnauba-12-35-Ounce-887101016/dp/B005SRV1PI/ref=asc_df_B005SRV1PI/?