The wooden brackets.
My daughter Janna needs additional shelves in the dorm to be attached in a concrete wall. There are 3 objectives: 1) The shelves has to be individually installed in a convenient space (the dorm is too small and has very limited space. 2) There is a need that it will be removed later when you need to transfer from other rooms. (Actrually we are only renting the dorm while Janna is taking Dentistry course 3 years to go from now). 3) Easy to install bracket is required.
With mentioned condition, I thought of a French cleat design however I come out a better and stronger way by using the sliding dovetail bracket instead. Here are some of the pictures how easy it is to make.
First step: Bracket shape and dimension. Using a 3/4×4 inches board, 6 brackets were made to be used in pairs for 3 shelves.
Second step: Cut strong wood of 1×1-1/2×4 inches for making the base board for the brackets. These will be attached to the wall in pairs.
Final step: Making the dovetail. Using a dovetail bit on my portable router, sliding dovetail were made for baseboard (tail side) and bracket (pin side). The baseboard will cater for the attachment to the wall using a concret tox (plastic inserts) and screws are hidden in the dovetail slot.
The final brackets:
It is stunningly strong bracket. The shelves are already installed (I dont have the pictures.) in the dorm.
Hope you have the idea. I will make more for my shoe rack, tool rack too. I hope this will add to your idea.