The ZQ600 Plus Series printers use the direct thermal method to print human-readable text, graphics, and barcodes. It incorporates a sophisticated print engine for optimal printing under all operational conditions. Direct thermal printing uses heat to cause a chemical reaction on specially treated media. This reaction creates a dark mark wherever a heated element on the printhead comes in contact with the media. Because the printing elements are arranged very densely at 203 dpi (dots per inch) horizontal and 200 dpi vertical, highly legible characters and graphic elements may be created a row at a time as the media advances past the printhead. This technology has the advantage of simplicity, as there is no requirement for consumable supplies such as ink or toner. However, because the media is sensitive to heat, it gradually loses legibility over long periods of time, especially if exposed to environments with relatively high temperatures or in direct sunlight.
