Saw something similar on Amazon but we wanted deeper shelves. The shelves pictured are 8" deep by 24" wide. Print without supports, mirror for the other side. Can be positioned either under the shelf or cradling. Cradling is definitely more structural. I printed in PETG but I'm sure PLA would be fine as long as you're not trying to put anything too heavy on them.
shelfbracket4.stl | 193.6KB |