Staz-on vote here too!! I have stamped the little zip bags for treats of beads and it worked well. Just need to allow it to set a minute or 2. If it is warm in your room that helps too. My house is always cold(40's) and I get trouble with things drying sometimes. I have only used black, green, brown and red Staz-on so cannot help with the white.
Depending what you are stamping on, I have used the Brilliance white but had to use my heat gun to set it...I think it may work on plastic if you used the gun to not heat the item but lightly run the hot air over the ink several times, only heating slightly at a time so not to damage the plastic. Just my 2 cents