Display for wooden plates

I was cleaning the shelf where all the 3D-printed and lasercutted objects are being presented and I was getting annoyed about some engraved plates of wood that just wouldn't stand straight because of the glass bottomplate.

So I decided to design a simple display where I could place them in. I made it of 3mm plywood. The engraved plates are 3mm thick so I decided to make the notch 4mm thick. Then it would be possible for some other plates to be placed in there to. It al is made with the laserc