Color 3D Printing?

The Zcorp printer squirts a small amount of binder into a bed of powder that makes it clump together.  It spreads a thin layer of powder over that and does it again for each layer.  It gets color by spraying ink into the powder, like an injket.  When done, you have to dig the model out of the remaining powder and blow it off.  It's very fragile, so the final dipping step was basically soaking it in super glue.

The Mcor is a blend of additive and subtractive I guess.  It is additive because it builds by adding layers of paper.  However it is subtractive in that each layer is cut out of a sheet.  With the Zcorp the extra powder is simply unused material, rather than removed material, and it can be used for subsequent builds.   With the MCor the extra paper is waste which is recyclable, but not directly usable by the printer.