The Sennelier Oil pastel range consists of over 100 colours including iridescent colours. Unlike oil sticks, oil pastels do not ever completely dry and remain heat sensitive. It is recommended that oil pastel works are sealed with oil pastel fixative In 1949, Parisian painter Henri GOETZ approached Henri Sennelier the famous artist materials manufacturer, about creating a wax colour stick for his friend Pablo Picasso, a long-time Sennelier customer and a frequent visitor to their store across the street from the Louvre museum, was looking for a medium that could be used freely on a variety of surfaces without fading or cracking. Their collaboration produced the incomparable Sennelier oil pastels. Originally available in a palette of classic hues, the colour selection was expanded with the addition of metallic and iridescent hues. Beyond these classic hues a selection of unique shades is available, and in particular a gradation of greys, required for a balanced palette. This evolution is the fruit of a long-standing collaboration with European and North American painters, who have worked with Sennelier in developing an exceptional palette of shades.