1. A pallet conveyor for a printing system comprising:a track;
a pallet to move on the track,
wherein the pallet includes a slider to operably couple the pallet and the track,
wherein the pallet supports a print substrate as the pallet passes through a print zone of the printer; and
a vacuum mechanism to selectively apply a vacuum at the pallet, such that a boundary of the vacuum applied at the pallet is synchronised with an edge of the print substrate.