Featuring water based dye ink and a real brush made from synthetic bristles, Pentel Sign Brush Pens are perfect for all types of creative work. Doodles, lettering, calligraphy, coloring. You name it, and you can probably do it with these pens! Thin to thick is easy to create by simply altering the pressure as you create a line. More creates something thick while much less results in almost a hair’s width line.