For outdoor signage and wide format printing, solvent based inkjet inks have become more and more important due to the outdoor weather durability requirements. There is a trend to solvent system from aqueous system on this particular application.Almost all of solvent based inkjet inks require a special solvent ink delivery system to prevent the severe solvents from damaging the printer, limiting solvent inks to work only on the solvent printers, which will extremely limit the application range of printers.After an extensive and exhaustive research and development, Graphic Digital invented a new concept of soft solvent based inkjet inks that work well with all types of printers, no mater solvent or aqueous printers, no matter thermal or piezoelectric head technologies, no matter wide formats or even deskjets, without changing printer ink supply system to be directly printed on uncoated vinyl for outdoor signage and poster printing applications with long term of weather durability. This unique high quality inkjet ink with much lower VOC is environmental friendly.The theoretical concepts, technical features, and testing results of soft solvent inkjet inks will be detail discussed in this paper.