Toning apparatus (23) for toning an electrostatic latent image, having image and background portions at different potentials on an imaging surface (16). The apparatus comprises an endless toning surface (21) coated with a layer of concentrated liquid toner and engaging the imaging surface (16) at a toning region. The apparatus additionally comprises a source of voltage connected to the toning surface (21) and electrifying the toning surface (21) to a voltage operative to selectively transfer at least a portion of the layer to image portions on the imaging surface (16). A developed mass per unit area (DMA) controller having an input indicative of the DMA on the imaging surface (16) is operative to adjust the DMA on the toning surface (21) in response to the input.
