developed for high speed printers with piezo printhead such as kyocera kjb4 printhead another formulation was developed using now nanumadit na 0716 additive it was mixed for humectation diethylene glycol 2 glycerin 2 and c 1 5 and 2 pyrrolidone 10 for drying and print quality water is added 26 to complete the base formulation in a second step it was added the magnetic loading 55 u2014 0716 nanumadit synthesized according to u s pat no 8 815 393 b2 in this formulation the ferrofluid contains 50 solids and is comprised of a cobalt and manganese ferrite functionalized with histidine using water as the carrier medium homogenization is carried out for 60 minutes at 230 rpm without heating wetting agents and biocide were added to adjust surface tension and control the growth of microorganisms this ink was printed using hp45 cartridge reaching average magnetization of 150 using idautomationscmc7 source size 12 and paper weights 90 g m2 this aqueous base formulation was prepared with the additive nanumadit na 2701 for the base of the ink were mixed glycerol 7 dantocol dhe 5 2 pyrrolidinone 7 cab o jet 300 10 and water 11 in a second step it was added the magnetic loading 60 u2014 2701 nanumadit synthesized as described in u s pat no 8 815 393 b2 in this formulation ferrofluid contains 50 solids and is comprised of a cobalt ferrite and barium functionalized with citric acid using water as the carrier medium the homogenization was performed during 60 minutes at 230.