Blabel is a python library to generate labels (typically for printing stickers) with barcodes and other niceties.

Some features:

• Generates PDF files where each page is a label (that's the way most label printers want it).
• Label layout is defined by HTML (Jinja) templates and CSS. Supports any page dimensions and margins.
• Builtin support for various barcodes, QR-codes, datamatrix, and more (wraps other libraries).
• Labels data can be provided as list of dicts (easy to generate from spreadsheets).
• Possibility to print several items per sticker.

To generate labels with Blabel you first need a HTML/Jinja template, and optionally a style sheet, to define how your labels will look like.

HTML item template (item_template.html)

Notice the use of label_tools (Blabel's builtin features). The variables sample_name and sample_id will be defined at label creation time.

<img src="{{label_tools.qr_code(sample_id)}}"/>
<span class='label'>
    {{ sample_name }} <br/>
    Made with ❤ @ EGF <br/>
    🗓 {{ label_tools.now() }}
</span>

CSS stylesheet (style.css)

Notice the CSS @page attributes which allows you to adjust the page format to the dimensions of your sticker. Also notice the pixelated image rendering. If your printer is black/white only with no greyscale support, this option will ensure crisp-looking barcodes, qr codes, etc.

@page {
    width: 27mm;
    height: 7mm;
    padding: 0.5mm;
}
img {
    height: 6.4mm;
    display: inline-block;
    vertical-align: middle;
    image-rendering: pixelated;
}
.label {
    font-family: Verdana;
    font-weight: bold;
    vertical-align: middle;
    display: inline-block;
    font-size: 7px;
}

Python code

In your Python script, create a LabelWriter linked to the two files above, and feed it a list of of dicts ("records"), one for each label to print :

from blabel import LabelWriter

label_writer = LabelWriter("item_template.html",
                           default_stylesheets=("style.css",))
records= [
    dict(sample_id="s01", sample_name="Sample 1"),
    dict(sample_id="s02", sample_name="Sample 2")
]

label_writer.write_labels(records, target='qrcode_and_label.pdf')

Result:

• Example with a barcode and a dynamically generated picture
• Ugly example with a logo and a datamatrix
• Example with date and QR code (sources of the example above)
• Example where the label data is read from spreadsheets
• Example where several items are printed on each page/sticker

You can install Blabel via PIP:

sudo pip install blabel

Alternatively, you can unzip the sources in a folder and type

sudo python setup.py install

Note: on macOS, you may need to first install pango with brew install pango.

Note: on some Debian systems you may need to first install libffi-dev (apt install libffi-dev). The package name may be libffi-devel on some systems.

DnaChisel is an open-source software originally written at the Edinburgh Genome Foundry by Zulko and released on Github under the MIT licence (¢ Edinburg Genome Foundry). Everyone is welcome to contribute !

Blabel was originally written to print labels for biological samples and is part of the EGF Codons synthetic biology software suite for DNA design, manufacturing and validation.