A method and means for enhancing the inner environment of a package containing perishable merchandise include taking a closable package containing perishable merchandise and placing in the package a multi-layered sheet including a plurality of layers comprised of moisture absorbing materials to absorb any residual moisture emanating from the perishable merchandise. The multi-layered sheet includes a quantity of CO.sub.2 generating material incorporated therein. The CO.sub.2 generating material is exposable to humidity and any residual moisture within the package and any moisture absorbing material to allow the CO.sub.2 generating material to emit an atmosphere of CO.sub.2 within the package from exposure to moisture within the air in the package, and to absorb any residual moisture in the package.