Simple Clamping system for crafting corners

I wanted a simple system to hold 3mm plywood in place for a dolls house kit I am building. I have used 8mm x 3mm magnets in 3D printed blocks to clamp the parts at right angles to one-another. I found it easier to make the right angle in two parts and glue them together rather than trying to print it as one part because with the right settings on my printer there was almost no post-processing required. Just slot two magnets into each part making sure to reverse the orientation of the magnets so that you do not have to worry about polarity. These clamps work fine with 3mm plywood and would probably work to clamp cardboard and foamboard as well. One of the edges is chamfered to help it rest into the corner properly, hopefully without getting glued there!