Piezography Neutral K7 inks are seven dilutions of pure carbon pigments which create Lab neutral to the human eye when viewed under 5000k and printed on Hanhemuhle PhotoRag or Innova Photo Cotton Smooth. These papers have a white on which this achromatic effect is achieved. Choose a warmer paper or a cooler paper, and the Neutral inks will warm or cool. A wide range of color tone is possible in this manner. The end result is a perfect marriage of ink and paper. A perfect monotone is produced. Inks are designed to fade less than 5% and shift less than deltaE 2, both below average human perception. These are the longest lasting inks available. There is a zero metamerism effect. The pigment particles are ground using a proprietary nano-technology. The fluid base in conjunction with the pigment produces a very non-clogging formula.