Ultraviolet Ink, also known as security ink, is invisible ink intended to not be seen by the naked eye. You need an ultraviolet light source to shine over your marking to make it visible. Using UV ink for your stamps is Stenography in it's finest form. Dry ink pad measures 1.75 x 2.75. Order your Ultra Violet (Invisible) 2 oz. Ink Refill Bottle With Dry Pad online here today!