Print Configuration

Print Settings configure how Colonnes sends output to printers and printer bridges. Open Print Settings from the application menu, from the Command Menu, or from the gear button in the Print dialog.

The dialog is organized with categories on the left:

  • Mode: choose the active output mode.
  • System Print: configure browser/system print output.
  • Receipt Printer: configure USB receipt-printer output, command settings, and direct or image rendering.
  • Bluetooth: connect a Bluetooth receipt printer and configure direct or image rendering.
  • Mac Alternative / CUPS: configure CUPS image output.
  • MQTT: configure broker publishing, JSON payloads, and image output.

The Print dialog still manages print-job defaults such as ticket format, breadcrumb, finished-task inclusion, and mark-as-finished behavior.

For the task-by-task print workflow, see Print Tasks.

System Print

System Print uses the browser or operating-system print dialog. It is the simplest mode because Colonnes does not need a printer ID, broker URL, Bluetooth device, or receipt-printer command language.

Available settings:

  • Font Size: text size used in browser printing.
  • Color: print in color, or disable color for black-and-white output.

Use System Print for office printers, PDF output, or any printer that should be handled by your operating system.

Receipt Printer (USB)

Receipt Printer mode sends output directly to a thermal printer installed on your system.

Configure:

  • Printer: the installed receipt printer.
  • Printer Model: the closest supported model or a generic model.
  • Print Type: Direct or Image.

Direct mode sends printer commands and text. It is very fast and works best when the printer language supports your characters.

Image mode generates a PNG before printing. It is better for special characters, mixed languages, precise padding, and visual tuning.

Advanced options include:

  • Printer Language: ESC/POS, StarPRNT, or StarLine.
  • Paper Width (Characters): columns per line for direct text output.
  • Feed Before Cut: blank feed lines before cutting the receipt.
  • Newline Character: LF or CR+LF.
  • Image Mode: Column or Raster image encoding.

Image settings include DPI, paper width in millimeters, left/right/top/bottom padding, font sizes, and a live preview.

For hardware compatibility, see Compatible Printers.

Bluetooth

Bluetooth mode connects to Bluetooth Low Energy thermal printers.

Configure:

  • Scan for printers: search for nearby Bluetooth receipt printers.
  • Connect: save the connected device ID and name.
  • Printer Model: choose the exact model or a compatible generic model.
  • Print Type: Direct or Image.

Direct output is faster. Image output is more tolerant of special characters and gives layout controls.

Bluetooth advanced options include paper width in characters, feed before cut, newline behavior, and image mode. Image output uses the same DPI, width, padding, font size, and preview controls as USB receipt-printer image output.

Mac Alternative / CUPS

Mac Alternative mode sends generated images to an operating-system print queue. It is designed for macOS and Linux printers managed by CUPS.

Configure:

  • Printer: the CUPS or system printer queue.
  • Prevent Trim: add a small guard line so drivers do not remove bottom padding.
  • DPI: image resolution.
  • Width: paper width in millimeters.
  • Padding: left, right, top, and bottom margins.
  • Font Sizes: breadcrumb, task, heading, and text sizes.

Use this mode when a printer is installed and visible to the operating system but does not respond correctly to direct receipt-printer commands.

MQTT

MQTT mode publishes generated print images to an MQTT broker. It is image-only and is intended for printer bridges, automations, and remote devices.

Configure connection settings:

  • Broker URL: for example mqtt://host:1883 or mqtts://host:8883.
  • Topic: the MQTT topic where print jobs are published.
  • QoS: delivery reliability level, from 0 to 2.
  • Retain: whether the broker keeps the last print message.
  • Username / Password: optional broker authentication.

The JSON Template defines the payload sent to the broker. Available variables are:

  • ${image_base64}: base64-encoded PNG image.
  • ${paper_width_mm}: paper width in millimeters.
  • ${paper_height_mm}: generated image height in millimeters.
  • ${timestamp}: current timestamp in milliseconds.

Default template:

{
  "data_type": "png",
  "data_base64": "${image_base64}",
  "paper_type": 0,
  "paper_width_mm": ${paper_width_mm},
  "paper_height_mm": ${paper_height_mm},
  "cut_paper": 1
}

MQTT image settings include DPI, width, padding, font sizes, and a live preview.