Abstract: Let (X,omega) be a compact hermitian 3-fold. We study the asymptotic behavior of Monge-Ampere volumes of hermitian forms that are dd^c-cohomologous to omega. We show that these are uniformly bounded if omega is pluripositive (dd^c omega >= 0), and that they are uniformly positive if omega is plurinegative (dd^c omega <= 0). We study the existence of such plurisigned hermitian metrics on various classes of examples. Joint work with D.Angella and H.C.Lu.