Sturdy Shop Shelves

In a never ending quest to be more organized (or less disorganized) I decided to redo some shelving in the shop.   This is a technique I've been using that 'traps' the horizontal supports in a dado cut into the uprights,   the shelves will withstand quite a lot of weight, they are easy to make and have no obstructions in the front area.  Important to try to make a tight fit for the shelf supports otherwise nothing to concern about.   Best of all it is a very inexpensive method of shelf construction.