This is a headboard that I just made for us. It is Big leaf Maple with Wenge posts. The maple is about 2-3/8 thick. Started at 3-1/4 before I flattened it. I used a router and a bridge to flatten it.
the maple slab is about 35" at it's widest and 97" long.
We plan to replace the bedspread so don't take off points for that.