Pebeo Studio Acrylics Auxiliaries, Phosphorescent Gel, 100 ml - Blue Gels that absorb the natural or artificial light and re-emits it in the darkness For best results, apply the gels thickly with a painting knife Designed for use with acrylic colors Use in Mixed Media applications with other Studio Acrylics Auxiliaries to expand creative possibilities Available in 5 colors, in 100 ml tubes