3x30ml Nano Premium Black Pigment Ink Refill Kit for Lexmark 14A Black Ink Cartridges for Lexmark Printer X2600, X2650, X2670, Z2300, Z2320 ... Particles: &lt;0.5 micron (Average&lt;100 nanometer); Stability: No settling in 2 years (at normal storage); Temperature: -12C no frozen and 50C no gelling; Lightfastness: 7-8 BWS; Rubfastness: 5 (Excellent); Waterfastness: 5 (Excellent); Gasfastness: 5 (Excellent).