Ink Wetter is an additive that makes any fountain pen ink have a ‘wetter’ flow. Great if you have a pen/ink combo that just doesn’t quite put out enough ink. Ink Wetter comes in a 1 ounce eyedropper bottle. Adding just five drops to a 45 ml bottle of ink will make a noticeable difference, but you can add as much or as little as suits your style. Be cautious and add it a small amount at a time because once it’s in, you can’t take it back out.