Felt tip pens thickness and thin, the 0.4 mm fineliner is suitable for drawing relatively thin lines, you can use it for writing protocols and some designed line designs; 1-2 mm felt tip pens are good for colouring books, signing work, design, art projects and hand lettering. Wide application: Artecho dual brush pen set is ideal for bullet journal, manga, colouring books, hand lettering, card making, motif stamping, sketching, illustration, hand lettering, planners, calendars, calligraphy and much more. High safety, Artecho dual brush pen set is all made of acid-free, odourless and non-toxic water-based ink. High quality, light fastness, vibrant colours, no ink leakage, easy to clean. Ideal gifts, Artecho dual brush pen set is an ideal art gift for family, friends for birthdays, Halloween, Thanksgiving, Christmas, etc.