Here is the difference between the economy and standard frames. The first one is the economy with the square cut ends and the small hole that shows. This is the slot that the backer fits into. The second photo is the standard cut frame, the angled cut corners that don’t show the slot for the backer.All of our kits come unassembled. This allows you to paint and stain your frames the way you want! It also allows you to complete the backer before assembling. This makes it a bit easier to decorate.