Hi Mode One
This is what Don came up with
Material facts (weight per 10cm):
5x5mm hardwood (Japanese cypress): 1g
4x4mm hardwood (Japanese cypress): 0.6g
4mm aluminum tube: 1.5g
3mm aluminum tube: 1g
3mm hardwood dowel: 0.33g
3mm bamboo dowel: Just a bit more.
I have not found 3mm bamboo or birch dowel down here in OZ.

To get birch dowel shipped from the US would cost me $50.00 us
just in shipping/ handling
Greg