A printer includes a vacuum belt assembly for moving print media in a media feed direction along a media path. The vacuum belt assembly includes: a plurality of spaced apart endless belts tensioned between first and second pulleys; a vacuum chamber for drawing print media onto an upper surface of the belts; and a plurality of vacuum antechambers communicating with the vacuum chamber, each vacuum antechamber having a perimeter opening for suction engagement with print media, a length dimension of each perimeter opening extending longitudinally in the media feed direction. A first perimeter opening of a first vacuum antechamber positioned towards an upstream side of the vacuum belt assembly is shorter than a second perimeter opening of a second vacuum antechamber positioned towards a downstream side of the vacuum belt assembly. The upstream and downstream sides are defined with respect to the media feed direction.