Sarasa Clip Milky Retractable Gel Pen Zebra Sarasa Milk Series features softly coloured, opaque inks that show up well on light and dark coloured papers. They can even be used on glossy photos! Like all Sarasa Clip colours, Sarasa Milk features water-based pigment ink that is acid free and water resistant for a long-lasting impression. A great pen for everyday writing and for scrapbookers and artists!