Poster Colour 36 - Cobalt Blue Pentel poster Color Cobalt Blue, Pentel Poster Color U Cobalt Blue No.23 comes in 30ml glass container bottle. Easy to use reliable. This poster color is convenient to use, no fuss paints with strong, vivid colors and excellent coverage density. \tRefills available in individual pots. \tTighten the bottle cap after each use. \tMix with water adequately making drawing smoother. \tColor: Cobalt Blue. 1 Piece of 30ml mini Bottle kit.