Hardwear P.D. Quick Topcoat locks your colour. butter LONDON's quick-drying, high-gloss topcoat protects your lacquer, and extends the life of your manicure. To revive a tired-looking manicure, apply a fresh coat to the entire nail. butter LONDON does not add formaldehyde, toluene, or DBP to any of its nail formulas. It's colour without compromise.