Various woven and knitted polyester fabrics were pretreated with formulations containing waterborne UV curable resins and silica particles to improve inkjet print quality. The UV curable resins and silica were chosen to impart the affinity of acid dyebased and direct dye-based inks onto the polyester fabrics. The low add-on of the selected formulation was applied to reduce the adverse effect on fabric hand without sacrificing the print quality. A print pattern with various areas and lines in cyan, yellow, magenta and black colors was designed and the pattern was inkjet printed on the various pretreated fabrics with a wide-format inkjet printer (Encad Novajet 750) to investigate the effects of the UV curable pretreatment on the print quality. Experimental results show that improved line quality in terms of the line width gain and the edge raggedness was observed for the lines printed on the pretreated fabrics. In particular, the 2 pt-line width of magenta color on the pretreated taffeta fabric was reduced by 13.8% and the 2 pt-line raggedness of yellow color on the pretreated taffeta fabrics was reduced by 80% compared to that on the untreated fabrics. Generally, increase in silica content inhibits inter-color bleeding onto the adjacent colored areas. For example, a 6% pretreatment formula of 10 parts UV curable resin and 6 parts of the silica particles can yield sharply defined images, while the printed fabrics still maintain a very good hand.