Storage is at a premium at our house, so Betty wanted to get the spices out of the cabinet, hence a spice rack was in order.   I made it from 5mm plywood, no frame just glue all the corners.   The rack came out plenty strong so 5mm is a good choice.    I made two of them one for each side of the sink.   I'll try and get a pic of the way they are attached (I glued on a 1/2" piece of wood then routed out a keyhole hanging slot in it).

Right side.

Right lower corner.

Left side.