The Black is permanent when left to dry. So you would not use it as a watercolour or try to mix it with other colours. To get the best results for artists it should be used to highlight and detail finished artwork. For crafters it’s perfect to use on a stamp as an initial outline then add colours. Illustrators and cartoonists would use it to outline, detail and block in. For clean lines always wait for a perfectly dry surface.
Black No.1
