To provide a surfactant that is useful for improving the image quality by the inkjet ink, in particular, the chroma (i.e. color saturation).

The inkjet ink prepared by using this surfactant shows one or more desirable characteristics such as improved chroma, bleed control, edge clarity and surface retention, thereby improving image quality. More specifically, the invention relates to surfactants that form relatively large aggregated structure (micelles) of geometry other than spherical, hence referred to as lamellae forming surfactants.