A belt for use in a papermaking process, such as in a long nip press having a cylindrical press roller and an arcuate pressure shoe which define a nip. The belt has a nip load zone which passes through the nip during an operation. The belt comprises a substrate having a coating on at least one surface thereof. The substrate is in the form of an endless loop and has a longitudinal direction. The coating has a plurality of grooves running in a center portion of the nip load zone, in which the number of grooves have at least one of a depth, width, cross-sectional shape, or spacing which is different from that of the others so as to vary the void volume in a desired manner.