A new perspective on Poisson's ratios of elastic solids is presented. We sh
ow that, by scaling the Poisson's ratios through the square root of a modul
us ratio, the transformed Poisson's ratios, n(1), n(2), n(3), are bounded i
n a closed region, which is inside a cube centered at the origin with a ran
ge from -1 to 1. The shape of this closed region, depicted in Fig. 1, looks
like a Chinese food, "Zongzi". With this geometric interpretation, any pos
itive definite compliance of an orthotropic solid can be easily constructed
by selecting any point inside the region, together with any three positive
Young's moduli and any three positive shear moduli. This provides a new in
sight to the admissible range of Poisson's ratios. We also provide an examp
le that the inequality proven by Rabinovich [6], i.e. v(12) + v(23) + v(31)
less than or equal to 3/2, is not generally true.