butter LONDON gives you make-up for your nails... Nail Foundation Flawless Basecoat is a silk-finish, stain resistant, non-toxic basecoat that provides the perfect foundation for 3 Free Lacquer. With matte results so beautiful, you can wear it alone. Nail Foundation Flawless Basecoat from butter LONDON, hides and smoothes tiny ridges and imperfections in the nail. It’s like cover-up, or foundation make-up for the nail, leaving a silky, matte finish when used alone. This treatment makes an excellent product for men who want an invisible, but immaculate manicure. When used as a basecoat, it provides a beautiful, smooth surface on which to paint, giving a wonderful result to the look of your lacquer.