A question for Matthew Alice:
What with Darfur, Iraq, and Anna Nicole Smith, it is probably shameful to ask, but...what is the difference between topcoat and basecoat in the world of nail polishing? Same formula, double the product to purchase?
-- SD, via e-mail
Chin up, SD. I think it's exactly because of Darfur and Iraq and Anna Nicole and Bobby Brown and Lindsay Lohan and Jessica Simpson that we occasionally need to slip into a deep funk ("We're doomed! We're doomed!"), overanalyze some body part, and see if we can't at least do something about that. Nail-polish purchases we can control. Sudan and Britney's underwear, we can't.
Grandma understands your weasely-eyed view of cosmetics in general. Her favorite online purchase used to be an all-natural, organic, ethically tested, horoscopically correct, free-range purple eyeliner based on an ancient Egyptian formula and handmade in a redwood forest by real hippies who had made at least three pilgrimages to India. Grandma was paying $15 for 1/20 of an ounce of the stuff. One day -- I think it was the day she short-sheeted the elves' beds -- we penciled out the price and showed her she was buying, basically, ground-up rocks for $4800 a pound. Made the elves feel better and put an end to Grandma's brief practical-joke career.
Anyway, after that experience we were plenty amazed to find out that in the world of nail polishing, there is a chemical and functional difference among top coat, base coat, and even the stuff billed as clear nail polish.
All basic formulas for nail goo include the same chemicals. Specialized formulas for base or top coats involve tweaking the basic ingredients -- a little more of this, a little less of that. Base coats are designed to stick to your fingernails with special tenacity. It's like priming a wall before you paint it; the paint adheres better if you wash and prime the wall first, and prime it with something formulated for that job only. A base coat also keeps cheesy, dye-based nail color from staining your fingertips.
Top coat formulas are jiggered to stick well to the colored layer of polish; to form a very hard, very shiny film; and (sometimes) to block UV rays that would fade the colored layer. The stuff billed as clear nail polish is somewhere in between. If there is a significant difference in price among the three within a single brand, well, that's a little harder to support. But the three polishes are slightly different in chemical ratios and should behave differently.
Whether the differences are significant enough to encourage you to spring for two or three bottles of what looks like identical, colorless nose drool with a brush, well, that's up to you. Stop reading here if you don't want to know some of the chemicals you're applying to your body: nitrocellulose, vinyl polymers (film formers); formaldehyde, vinyl resins (slightly different film formers); dibutyl phthalate, tricresyl phosphate (for flexibility); acetates, ketones, toluene, xylene, ethyl alcohol (diluting agents); mica, fish scales, guanine, gold, silver, copper, titanium dioxide, bismuth oxychloride (coloring agents). All swimming in a base of ethyl acetate.