^MD sets the print darkness as a relative offset from the printer's current stored darkness value. Positive values increase darkness (more heat, darker print); negative values decrease it (less heat, lighter print).
This command does not set an absolute darkness level — it adjusts relative to the printer's configured baseline. If your printer is set to darkness 10 and you send ^MD5, the effective darkness for that format is 15. This makes ^MD format-specific without requiring you to know or reset the printer's global setting.
The valid range is −30 to +30. Out-of-range values are clamped to the printer's supported minimum and maximum.
Darkness affects barcode scannability significantly. Too dark and bars bleed together (barcode widens and may fail to scan); too light and bars don't have enough contrast. Thermal label media, printer speed, and print head wear all interact with darkness — the right value is usually found empirically for each media/printer combination.
^MD applies to the entire current format. You cannot set different darkness values for different fields within a single label.
Syntax
^MDd
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| d | integer (−30 to +30) | 0 | Darkness adjustment relative to the printer's stored value. Positive = darker, negative = lighter. |
Examples
Increase darkness by 5 for a bold print
Try in Viewer^XA ^MD5 ^FO50,50^A0N,40,40^FDDark Print^FS ^FO50,110^BY2,3,80^BCN,80,Y,N,N^FD123456789^FS ^XZ
Decrease darkness for light thermal media
Try in Viewer^XA ^MD-3 ^FO50,50^A0N,36,36^FDLight Media Label^FS ^XZ
Common Mistakes
- !Treating ^MD as an absolute darkness setter — it's a relative offset, so the result depends on the printer's stored value.
- !Setting darkness too high for barcodes — bars bleed and the barcode fails verification.
- !Using ^MD to compensate for worn print heads — a worn head needs servicing, not more darkness.