Doug, 100 percent white will work if you can flash to prevent build up and your colors muddying up but I would NOT recommend the 100 percent or the flashing. a 85/15 base/wite mix does the trick for me. also it really helps to use chino base in your overprint colors ith 160- 200 mesh. of course thats relative to what kind of mesh your using. I also like the 70/90/70 squeegie durometor but again it depends on your press and your printing technique. why not just run straight up discharge?