Annie, are you resizing the whole double page to 600 pixels or each individual one? If you are putting both together, try resizing to 1200 pixels instead. Also, I find that sometimes, it gives better results to save a full-size copy in jpg format and resize that jpg image instead of the pspimage. And if it still does not seem to give a good result, add a little sharpness with Adjust > Sharpen > Sharpen. Remember that you are going from 7200 pixels to 600 pixels, so there are some lost details.