Abstract: A process for manufacturing a sheet of grid-patterned membrane for use in vacuum bagging processes which includes the steps of selecting equal size sheets of open weave mesh material, elastomeric material, and separator material. The sheet of elastomeric material is aligned over the sheet of mesh material while the sheet of separator material is aligned over the opposite side of the mesh material and then tightly wound onto a drum to create a continuous roll structure. The continuous roll structure is then autoclaved with sufficient pressure and temperature until the elastomeric material partially extrudes through the openings on the sheet of mesh material and makes contacts with the sheet of separator material to create a well defined grid pattern on one surface of the sheet of elastomeric material. After curing, the sheets of mesh material and separator material are separated to produce a sheet of grid-patterned membrane which may be cut to any desired size.