2.5D Simple Chair and Table

Let's imagine a chair laying on its side. That way we can draw it nicely with inkscape.

The side of the chair is duplicated. Both have 'height: 6mm', but the copy gets an additional 'raise: 40mm' attribute.
The darker part forms the seat and the back of the chair, it has 'height: 46 mm'.

The legs have that curved inner shape. This should make it easier for your 3D-Printer to succeed without support. chair_csupp.stl has a 0.8mm fin in the center that should server as support between left a