600ML UV Dye refill Ink for T048 77 78 79 98 99 and CISS High quality refill dye ink Particles: &lt;0.5 micron (Average&lt;100 nanometer); Stability: No settling in 2 years (at normal storage); Lightfastness: 7-8 BWS; Rubfastness: 5 (Excellent); Waterfastness: 5 (Excellent); Gasfastness: 5 (Excellent).