The Art Studio's Graphic ProDuo Markers are alcohol-based felt tip pens that are the ideal choice for artists wanting a high-quality, versatile marker. As the name implies, each pen has a different shaped nib at each end - one end is a fine tip and great for small details, while the other is broad and perfect for filling in large blocks of colour. They can be used on all sorts of surfaces like paper, plastic, cloth and metal, as the alcohol in them dries very quickly and stays permanent. The Colourless Blender is an amazing tool that allows you to blend two colours together in a natural looking way, similar to a watercolour painting! Simply draw your lines, then press the colourless blender into the paper and draw over the lines to merge them together.