Among the 120 tones, there are also 4 interference colours, which is to say they reflect two different colours according to the viewing angle. The line also includes 6 iridescent metallic colours.

Sennelier maintains a tradition of artisanal fabrication, subject to strict and constant quality control. Each stage of production is rigorously tested in the laboratory.
A product is only launched on the market after a serie of tests confirming that it meets very specific requirements for colour, lightfastness, consistency, saturation, value, pH, and drying time. All products in the extra-fine acrylic line conform to the ASTM (American Society for Testing and Materials) standard D4236 concerning toxicity and safety. The colours also meet the ASTM D5098 standard, testifying to their lightfastness.

Sennelier extra-fine acrylic offers the possibility of working with layers or wash drawings, in combination with other techniques such as pastels, charcoal, or ink, in overlays, and by creating collages and inlays of various materials. It can be used outdoors and in the studio. It provides very good adhesion on many non-oily surfaces: paper, canvases, cardboard canvases, wood, fabric, cement, plaster, some plastics and metals. It can be worked with a brush, painting knife, metal spatula, directly from the tube to obtain thick lines, or even with fingers. Thanks 60ml tube (2 fl oz) 120 colours are available in 60ml/2 fl oz and 200ml tubes/6,7 fl oz to excellent spreading properties, there is no difficulty mixing any of the Sennelier extra-fine acrylic colors to obtain an infinite number of shades, without altering the luminosity of tones. They are excellent for coatings and can be mixed with Sennelier additives to modify the texture, viscosity, transparency, or luminosity at will.

Sennelier extra-fine acrylic has little odor and dries rapidly to create a permanent, insoluble, non-cracking, non-yellowing, water resistant film. The variation in rendering that may occur after drying is very small or nonexistent depending upon the shade.epending on the nuances.