John Howard Sanden, noted portrait painter, author and teacher, developed the ProMix System of flesh and neutral tone oil colors. It allows the artist to obtain delicate variations of skin tones quickly and consistently with reliability and control. Non-toxic. The set contains all 10 specially formulated Professional Oil Colors (37 ml each), ProMix System Color Chart and Mixing Guide and The ProMix Color System "Color Mixing for Portrait and Figure Painting" book. Made in the USA.