Conté pastels, also known as Conté sticks, are hard artists' chalks in a variety of colours. They are harder than pastels and contain a greater pigment density; they are square in cross-section.
They are used for drawing, generally on a rough paper that holds pigment grains well. They can also be used on prepared primed canvasses for underdrawing for a painting.
Their square profile makes them more suitable for detailed, hatched work; as opposed to the bolder 'painterly' drawing style demanded by soft pastels.