Happy Free Design Friday a day early!
Wanted to come up with something easy and nice. I hope you like. 7.5" x 5.75" Opening is 6.5" x 4.5".
The frame is PG Medium Walnut, connectors are PG Medium Basswood ( you can use anything, I just liked the contrast)
When you are putting it together you have to kinda pull up on the connectors where they have the nub so it can slide down. Put a short and a long side together first, then another long side, then put the connectors on the short side (at both ends) and push down onto the rest of the frame.
If you want a solid back just print one of the inside pieces without the center cutout!
Hope you like!
File 1 is the frame, File 2 is the Acrylic