Interface: MediaDescriptor

Base media descriptor.

Each driver extends this with family-specific fields (print area dots, margins, head geometry, etc.). Structural typing means any superset passes cleanly to PrinterAdapter methods.

Examples

// Brother QL continuous tape (single-colour)
const m: MediaDescriptor = {
  id: 259,
  name: '62mm continuous',
  widthMm: 62,
  type: 'continuous',
};

// Brother QL two-colour tape (DK-22251)
const m: MediaDescriptor = {
  id: 251,
  name: 'DK-22251 62mm',
  widthMm: 62,
  type: 'continuous',
  palette: [
    { name: 'black', rgb: [0, 0, 0] },
    { name: 'red', rgb: [255, 0, 0] },
  ],
};

// Die-cut address label (auto-rotates landscape input)
const m: MediaDescriptor = {
  id: 274,
  name: '62×29mm',
  widthMm: 62,
  heightMm: 29,
  type: 'die-cut',
  defaultOrientation: 'horizontal',
  cornerRadiusMm: 3,
};

// Round die-cut label
const m: MediaDescriptor = {
  id: 363,
  name: '24mm Ø',
  widthMm: 24,
  heightMm: 24,
  type: 'die-cut',
  cornerRadiusMm: 12, // widthMm / 2
};

Properties

Property	Modifier	Type	Description
category?	public	| "address" | "shipping" | "file-folder" | "multi-purpose" | "name-badge" | "barcode" | "price-tag" | "continuous" | "cartridge" | "tape" | "die-cut"	Coarse category for grouping in docs and UI. Driver-extensible; common values listed for cross-driver consistency.
cornerRadiusMm?	public	number	Corner radius (mm) of die-cut labels with rounded corners. Only meaningful for die-cut media. Undefined or 0 = sharp corners. For round labels, set this to widthMm / 2 so the rounded rectangle degenerates to a circle.
defaultOrientation?	public	"horizontal" | "vertical"	Hint for how the user is expected to author content for this media. Drives the auto-rotate decision in print(): - 'horizontal' — long axis horizontal when reading (landscape). Driver rotates 90° in the family-specific direction when input matches landscape dimensions. Examples: 89×28 mm address labels, 12 mm narrow tape with a name on it. - 'vertical' — long axis vertical when reading (portrait). Driver passes through. - undefined — driver passes through. Recommended for continuous wide tape (62 mm) where users may go either way.
heightMm?	public	number	Physical height/length in mm. - Undefined = continuous (variable length; printer cuts to content). - A number = fixed length (die-cut labels, tape segments).
id	public	string | number	Unique identifier within the driver family.
name	public	string	Human-readable name, e.g. "62mm continuous" or "DK-22251".
palette?	public	readonly PaletteEntry[]	Inks this media supports, beyond the implicit white substrate. - Undefined = single-colour black-on-white. Driver renders via renderImage (luminance threshold + optional dither). - Defined = multi-plane media. Driver renders via renderMultiPlaneImage with this palette. For DK-22251 (the only multi-ink media we ship today): [{ name: 'black', rgb: [0, 0, 0] }, { name: 'red', rgb: [255, 0, 0] }]
printMargins?	public	{ bottomMm: number; leftMm: number; rightMm: number; topMm: number; }	Insets (mm) inside the media bounds where the printer may clip a design (paper-feed tolerance, head edges, die-cut slack). Informational — for label designers and previews. Drivers do not enforce these; protocol-level margins (head pin offsets, head-dot fitting) are handled separately by family-specific fields. When present, all four edges are required (pass 0 where there is no margin). Omit the whole field when the entire media area is safe to design within.
printMargins.bottomMm	readonly	number	-
printMargins.leftMm	readonly	number	-
printMargins.rightMm	readonly	number	-
printMargins.topMm	readonly	number	-
skus?	public	readonly string[]	Vendor SKUs for this media — e.g. Dymo '30321' / 'S0722400', Brother 'DK-22251'. Mixed formats allowed; the registry does no validation. Used by docs (per-device "supported media" table) and by UI consumers that let users search by SKU.
targetModels?	public	readonly string[]	Devices this media is compatible with. Driver-defined string set; matched against PrintEngine.mediaCompatibility. Examples: ['standard'] (paper roll fits 672-dot heads), ['4xl', '5xl'] (wide-head only), ['duo'] (D1 cartridges). Omit = fits every device in the family.
type	public	string	Media type classification — driver-specific string values. Common values: 'continuous', 'die-cut', 'tape'. Drivers may define additional values as needed.
widthMm	public	number	Physical width in mm.