A printing device transfers slide dependent information onto glass surfaces such as a glass slide for holding a medical specimen. A single slide is transferred from a storage section, passing under a thermal print head. The thermal print head defines and transfers an image from an ink media onto the slide as the slide passes across the print head. The print head utilizes pixel like heating elements to apply the desired image. The ink media moves in tandem with the motion of the slide, presenting a continuously fresh section of ink between the print head and the slide throughout the printing process. The information on the slide should be both human and machine readable to reduce any chances of misidentification of the specimen as to the patient. The ink media is endures any chemical processes and handling encountered throughout the expected life of the slide.