Josephine asked for some live-edge shelves for DVDs.
I found some nice birch planks on Craigslist:
Then they needed a little more dressing up/contrast. So after planing off the back edge and sanding them a little bit, I cut them to size and applied stain to about half of each board. Then I varnished them, which unfortunately yellowed them a little, but they still looked good.
To install them as floating shelves on a concrete wall, I inserted 1/4″ lag bolts into the wall, cut off the heads, drilled matching holes in the back of the shelves, and slid them onto the bolts. I put a bead of silicone along the back too.