I like how these 2 projects use the zig-zaggy Lack wall shelf from Ikea. The first project packs a fair bit into a small space and makes use of materials from an old scratching post. The second project uses 2 shelves. Both use shelf brackets from a hardware store to secure the shelf to the wall and to the bookcase.
I love this – thanks for posting it!
where can you buy something similar to the red shelf