A blend of dyes are used in this water-based ink which results in unique undertones when diluted with distilled water for a wash. Compatible with dip pens, brushes, airbrushes, and fountain pens. Close cap tightly after use. Do not mix with acids, or use as tattoo ink. Not launderproof. To keep pens in good repair, clean with water or Higgins Pen Cleaner no longer than 1 week after last use. Made in the USA