Liquitex Professional Acrylic Ink Pen Cleaner designed for cleaning Acrylic Ink from paint brushes, airbrush parts, technical and dip pens. Use the clear, low-odor formula to rinse your tools after use and before the ink has dried. If the ink has already dried, soak the tool in Pen Cleaner, leave it to work for a few minutes, then test to see if the crusted color comes off and then rinse with water. Leave for a little longer if the paint is thick.