Plain English

Selects the **physical printing mechanism** the firmware should drive. `^MTT` = **Thermal Transfer** — the print head heats a wax/resin **ribbon** which transfers ink onto plain label stock; the ribbon is consumed. `^MTD` = **Direct Thermal** — the print head heats specially-coated, heat-sensitive label stock directly, blackening the coating where heated; **no ribbon** is used. The setting tells the printer how to drive head energy, ribbon-low sensors, and ribbon take-up motor — not just a print-quality knob.

When to use

**Setting must match the loaded media physically**, not your preference. Mismatch is silent and visible only in output: `^MTT` on direct-thermal media → print head heats a non-existent ribbon and the heat-sensitive coating burns intermittently or unpredictably; `^MTD` on thermal-transfer media → head heats but no coating exists to react and no ribbon is engaged → output is **completely blank** (clean media still passes through). Persisted settings are usually written via `^JU` (configuration save) so this command takes effect for subsequent jobs until the next `^MT` is sent. Most printers expose the same setting in the front-panel menu.

Syntax

^MTa

Parameters

ParameterDescription
aMedia type: `T` = Thermal Transfer (ribbon required), `D` = Direct Thermal (heat-sensitive media, no ribbon)

Example

^XA
^MTT
^XZ

Switches the printer into thermal-transfer mode (ribbon required). If the printer is loaded with direct-thermal media but `^MTT` is set, output will be blank — the head heats a non-existent ribbon and never marks the heat-sensitive coating. Always pair `^MT` with the actual loaded stock.

Try it in the playground View all ZPL commands