An image forming system includes a fluid applicator unit, a substrate positioning unit, and a fluid collector assembly. The fluid collector assembly includes a collector substrate, a collector advancement unit, and a collector control module. The fluid applicator unit may apply fluid to a substrate. The substrate positioning unit may position the substrate in a printzone to receive the fluid from the fluid applicator unit such that a first portion of the fluid remains on the substrate and a second portion of the fluid does not remain on the substrate. The collector substrate may collect the second portion of the fluid in the printzone below the substrate. The collector advancement unit may advance the collector substrate along a collector transport path below the substrate in the printzone. The collector control module may control the collector advancement unit to selectively advance the collector substrate along the collector transport path in response to application of the fluid to the substrate by the fluid applicator unit.