what reason of floating dirty for offset transfer printing?

floating dirty
Phenomenon: in the non-image areas of light color gets dirty, not from printing and dyeing, so easy to erase.
Reasons : sublimation offset ink,offset transfer printing ink,sublimation offset transfer ink
(1) ink is quite soft part of the ink into the fountain solution emulsified in the formation of oil in water type emulsion by the role of fountain solution.
(2) chemicals and wetting agents in the paper contribute to ink emulsification.
(3) fountain solution containing soaps or detergents to cause the ink emulsion.