What I do is spray the two colors, then put a thick layer of clear over the two colors. Make sure neither color is affected the primer base, or you may end up spraying one color first and the second later (i.e. if you're painting white/black, then spray white first then black). Then clear the whole thing, the clear will "gloss" over the paint "step"
To get a good mask, brush Future Floor Finish over the masking tape after you apply it, this little clearcoat makes sure no paint can get under the tape.
