Picture Frame Bracket to fit IKEA Ribba frames

We recently bought some Ikea picture frames and were having trouble mounting them on the wall. I came up with this design for two brackets which screw to the back of the deep frame enabling a piece of string, cord or wire to be stretched across between the brackets to facilitate mounting the picture.

Simple but effective I think. (A bit like me!!!)

this is the picture frame it fits
http://www.ikea.com/gb/en/catalog/products/70153160/

I modified the design after printing out the first two to make it easier to get the screwdriver to put the screws in.

This is the second iteration of the design but might still need to be modified.