This investigation seeks to identify the effects of partial vacuums on the steady-state drying rate of cotton plates. Five pressure levels between atmospheric pressure and 33.6 kPa (20 " Hg vacuum) were tested in an aluminum vacuum chamber. Improvements in steady state drying rates on the order of 62% were observed at the lowest pressure level. The hoped-for design points were not discovered. Both theoretical and experimental values of the mass transfer rate are developed.