This is Gowanus Furniture Co., after all.
Not Gowanus Cutting Board Co.
This is the beginning of a new system of shelving - in process. They'll be relatively simple shelves, in a variety of lengths (8"-24"), ranging from 8-10" deep.
The shelf is the vertical portion to the left, the horizontal part will be against the wall. They'll be strong enough to hold some books, or are great next to your bed.
This prototype is made from 4/4 walnut, so it's about 7/8" thick. The final version will be 5/4, so a little more than 1" thick.
You can see the two pieces joined together with a walnut spline. Will be pretty strong, but will find out exactly how strong...
The shelf will be mounted to the wall in a similar way to the cutting boards are - two rubber bumpers - very easy to mount, dismount, it'll be sturdy, and look cool too.
In this picture you can see a little lip on the bottom:
It's that little bit to the left of the "Y" in Bessey. That lip will fit into a notch at the top of anther shelf, so that you can stack them up your wall without gaps between them.
Great shelves you can buy as needed, arrange, rearrange, and keep from apartment to apartment.