An inkjet printing apparatus for printing continuous tone images on a receiver in response to a digital image, including a structure defining a plurality of colorant or colorant precursor receiving chambers, and another structure defining at least one mixing chamber for receiving a plurality of microdrops...http://www.google.com.au/patents/US6097406?utm_source=gb-gplus-sharePatent US6097406 - Apparatus for mixing and ejecting mixed colorant drops
