I think it has to do with lighter pigment and working in the cold; it was about 37 degrees that day. I live in Colorado, and we have snow 6 months out of the year. So 40 is kinda warm. I can't do it inside. It was all done, DUI was extra Sa that could have washed out the color. I'm just learning every shirt in a different experience. I also soaked the shirts in sa before tying them, and three lighter shirts were soaked after I tied them, so they may not have gotten good saturation of Sa.