the exisitng water-based inks can easily fade in harsh weather including direct sunlight,rain,and wind, etc. solvent-based inks help to enhance outdoor durability with inkjet pinters. printhead technology has developed from the thermal type to the piezo printer head, which can utilize other types of inks as well as water-based inks.a thermal printer is basically comprised of a thermal head, which prints by generating heat and causes a chemical reaction whth solvent-based and oil-based inks.oil-based inks are compatible whth only coates materials likes pvc flex,pp synthetics,pvc vinyls and backili films.but solvent-based inks can be used on uncoated materials. in other words,solvent-based inks were created from customers and printer manufacturers desire to enhance out door durability.