My Mom is an NW20 year round, I vary from NW20 in the winter to NW25-30 in the summer. She didn't care for the Select SPF very well, which I liked, I gave her my Select Moistureblend that was toooo moist for me.
So, I mixed her NW20 w/my NW25 in one of the little MAC jars until I get juuuust the perfect color. Couldn't have gotten a better match!