Corkscrew Ink Tube
A corkscrew-shaped ink chamber, which distributes the liquid over an area vast enough to equal two ink chambers. Yeah, the plastic shell has to be bigger to accommodate all those coils, but, by the looks of it, not dramatically so. Besides, it stands to reason that the extra plastic needed to manufactured one T&T pen is still less than the material needed to produce two regular pens - good news for the environment.
Source: fastcodesign.comAdded: 5 May 2011