A comparative study is carried out to investigate seven different organic solvents in pretreatment and incorporation in printing pastes of polyester, polyester cotton blends, 50/50 and 65/35 fabrics. The substrates are printed with their compatible dyes, disperse and disperse/reactive. The presence of organic solvents increases the suitability of the dye molecules, which facilitates their transfer from the printed film into the fabric during fixation. All the factors influencing the pre-treatment and printing efficiency of the substrates are investigated in detail. The K/S (the color yield of the printed samples) values of the prints along with the water absorption and tensile strength measurements are also determined. (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 108:1,064-1069, 2008.