chalkboard

I'm building a chalkboard for my wife, which will be half-lap corners. 1/2" wide by 3/8" deep rabbet in a 3" wide walnut frame. Planning on using 1/4 melamine which I will paint with chalkboard paint. What is the best method for holding the chalkboard in place?

I build frames for a chalkboard sign company and I need a quick strong way to make mortise and Tenon joining. I've created a link so you can see what I'm up against. Thanks, Dave

Hey guys, decided to try a small project and it came out really nice. The wife is a fan of etsy website which sells handmade crafts and stuff, and someone is selling this thing for quit a bit, with $40 of materials and like 4 hours time i made the same thing. 1/2" birch plywood back. Would have...