I built these a while back. They are built from treated southern yellow pine. I have probably sold at least 200 sets of these over the last few years. They are my design, using the best I’ve seen from others. The main framework is out of 2×4 and 2×6 with 5/4×6 for the arms and 1×4and 1×2 slats. I designed the footrest to match and they will actually balance without touching the chair or bench on a flat surface. The backs of the chairs have a contour and the bench has a contour on each side of the back. The people in them are high school kids that worked for me.