A textile inkjet ink formulation essentially depends on the chemistry of substrate. It is important to select the right chemistry of the dyes or pigments and formulate inks that provide good visual and technical properties on the target substrate. However, limitations applied by the working window for available print head technologies, such as the viscosity, compatibility of ink with print head components, temperature restrictions, stability, pH sensitivity, particle size etc, require the inkjet formulator to understand the chemistry of the substrate and colorant, application method, processes involved in the preparation of fabric, post treatment of fabric and application conditions, to be able to formulate ink that provide acceptable visual, optical and technical properties. This paper reviews the current state-of-the-art Ink chemistry required for natural and synthetic fabrics.