A method for delivering a pigment dispersion and an inverted retention aid emulsion to a papermaking process, the method comprising: injecting the pigment dispersion and the inverted retention aid emulsion into a process line of the papermaking process; wherein the pigment dispersion comprises titanium dioxide; and wherein the process line is located downstream from a screen and upstream from a headbox, wherein the pigment dispersion and the inverted retention aid emulsion are injected in the same cross-section of the process line and simultaneously in time, and wherein the pigment dispersion and the inverted retention aid emulsion are injected via separate nozzle devices, wherein each nozzle device comprises: a first conduit having at least one inlet and at least one outlet; a second conduit having at least one inlet and at least one outlet, wherein the first conduit secures to the second conduit and traverses the second conduit; a mixing chamber having at least one inlet and at least one outlet, wherein the second conduit secures to the mixing chamber and wherein the at least one outlet of the first conduit and the at least one outlet of the second conduit are in fluid communication with the mixing chamber; and wherein each of the nozzle devices is operably connected to the process line, wherein the pigment dispersion and the inverted retention aid emulsion are introduced into the at least one inlet of the first conduit of a nozzle device and an aqueous liquid is introduced into the second conduit via at least one inlet of each nozzle device. injecting the pigment dispersion and the inverted retention aid emulsion into a process line of the papermaking process; wherein the pigment dispersion comprises titanium dioxide; and wherein the process line is located downstream from a screen and upstream from a headbox, wherein the pigment dispersion and the inverted retention aid emulsion are injected in the same cross-section of the process line and simultaneously in time, and wherein the pigment dispersion and the inverted retention aid emulsion are injected via separate nozzle devices, wherein each nozzle device comprises: a first conduit having at least one inlet and at least one outlet; a second conduit having at least one inlet and at least one outlet, wherein the first conduit secures to the second conduit and traverses the second conduit; a mixing chamber having at least one inlet and at least one outlet, wherein the second conduit secures to the mixing chamber and wherein the at least one outlet of the first conduit and the at least one outlet of the second conduit are in fluid communication with the mixing chamber; and wherein each of the nozzle devices is operably connected to the process line, wherein the pigment dispersion and the inverted retention aid emulsion are introduced into the at least one inlet of the first conduit of a nozzle device and an aqueous liquid is introduced into the second conduit via at least one inlet of each nozzle device. a first conduit having at least one inlet and at least one outlet; a second conduit having at least one inlet and at least one outlet, wherein the first conduit secures to the second conduit and traverses the second conduit; a mixing chamber having at least one inlet and at least one outlet, wherein the second conduit secures to the mixing chamber and wherein the at least one outlet of the first conduit and the at least one outlet of the second conduit are in fluid communication with the mixing chamber; and wherein each of the nozzle devices is operably connected to the process line, wherein the pigment dispersion and the inverted retention aid emulsion are introduced into the at least one inlet of the first conduit of a nozzle device and an aqueous liquid is introduced into the second conduit via at least one inlet of each nozzle device.