LabelAssister

A WYSIWYG label editor for the Brother QL-700 thermal printer (Linux). The little sister of your Brother: she helps you design and print labels, the same pixels on screen and on paper (300 dpi).

Features

• Roll widths: 12, 17, 24, 29, 38, 50, 54, 58, 62 mm, with free length in millimeters
• Printable area shown on the roll (from brother_ql; estimated for the non-native 17/24/58 mm rolls)
• Text blocks: any system font, size in mm, bold/italic/underline, alignment, 0–270° rotation, adjustable block width
• Images and PDF: insert JPEG/PNG images or PDF pages (with page selection), rendered at 300 dpi
• Full editing: mouse dragging and resizing, arrow keys (0.5 mm steps, 0.1 mm with Shift), Del to remove
• Millimeter grid, zoom and "Fit" view
• Automatic length minimization to save tape
• Projects: save/load to JSON (images embedded), export to PNG or PDF
• Printing: multiple copies, auto-cut, automatic printer detection
• International: English by default, French included

Requirements

• Python ≥ 3.10
• A Brother QL-700 connected over USB
• Linux (udev) — other platforms untested

Installation

Requires uv and Python ≥ 3.10.

git clone https://your-forge.example/labelassister.git
cd labelassister
uv sync

Then start the editor:

uv run labelassister

Without installing

You can also run the application straight from the source tree:

uv sync
uv run python app.py

Releasing a new version

uv run bumpver update --patch

bumpver bumps the version (and rolls the date with --YYYY --0M --0D --patch when a new day's release starts), regenerates uv.lock via its pre-commit hook and creates the version commit itself.

Printer permissions

The printer needs to be reachable without sudo. Install the provided udev rule once:

sudo cp resources/udev/60-brother-ql.rules /etc/udev/rules.d/
sudo udevadm control --reload && sudo udevadm trigger

If the printer shows up as a USB drive instead of a printer, disable the "Editor Lite" mode on the device.

Usage

Start the editor (see above), choose "Printer…" in the toolbar, pick the backend (linux_kernel → /dev/usb/lpX or pyusb) and press Detect.

Create text blocks or drop in images/PDFs, arrange them with the mouse or the arrow keys (Shift for fine 0.1 mm moves), then press Print.

Keyboard shortcuts: Ctrl+Q quits, arrow keys move the selected block.

Compatible label cartridges

Reference	Label type	Color / Printing	Dimensions / Packaging	Supported by LabelAssister
DK-44205	Removable paper	Black on white	62 mm x 30.48 m	Yes
DK-22212	Continuous film	Black on white	62 mm x 15.24 m	Yes
DK-11218	Pre-cut labels (round)	Black on white	Diam. 24 mm (1,000 labels)	No
DK-11209	Address labels	Black on white	29 x 62 mm (800 labels)	No
DK-22225	Continuous paper	Black on white	38 mm x 30.48 m	Yes
DK-22223	Continuous paper	Black on white	50 mm x 30.48 m	Yes
DK-N55224	Continuous paper adhesive-free	Black on white	54 mm x 30.5 m	Yes
DK-22205	Continuous paper	Black on white	62 mm x 30.48 m	Yes
DK-11219	Pre-cut labels (round)	Black on white	Diam. 12 mm (1,200 labels)	No
DK-11204	Pre-cut labels	Black on white	17 x 54 mm (400 labels)	Yes
DK-22210	Continuous paper	Black on white	29 mm x 30.48 m	Yes
DK-11202	Shipping labels	Black on white	62 x 100 mm (300 labels)	Yes
DK-11201	Pre-cut labels	Black on white	29 x 90 mm (400 labels)	Yes
DK-44605	Continuous paper	Yellow	62 mm x 30.48 m	Yes
DK-11221	Pre-cut labels (square)	Black on white	23 x 23 mm (1,000 labels)	Yes
DK-11203	Pre-cut labels	Black on white	17 x 87 mm (300 labels)	Yes
DK-22214	Continuous paper	Black on white	12 mm x 30.48 m	Yes
DK-22113	Continuous film	Black on transparent	62 mm x 15.24 m	Yes
DK-22606	Continuous film	Black on yellow	62 mm x 15.24 m	Yes
DK-22211	Continuous paper	White (white labels)	29 mm x 15.24 m	Yes
DK-11208	Pre-cut labels	Black on white	38 x 90 mm (400 labels)	Yes
DK-11207	CD/DVD labels	Black on white	Diam. 58 mm (100 labels)	No

Labels are matched by size, not by reference number. Continuous rolls of 12/17/24/29/38/50/54/58/62 mm and the die-cut sizes handled by brother_ql (17x54, 17x87, 23x23, 29x42, 29x90, 38x90, 62x29, 62x100…) are supported; round and CD/DVD labels are not.

Configuration

Preferences (default label size, font, grid, language) are stored with QSettings in ~/.config/LabelAssister/LabelAssister.conf, following the XDG convention.