Choose the representation
The Data Matrix library exposes Text, C40, X12, and ASCII encoders. That choice matters: mostly lowercase input fits Text well, while uppercase input can avoid character-set shifts with C40. The README includes a complete example that turns the repository URL into a GIF using an Encoder instance.
This is a useful example of making an algorithm's constraints visible in its API. A caller selects the encoding, supplies text, then requests the rendered bytes. Encoding and writing a file remain separate responsibilities.
Make the edge cases explicit
The X12 path has a narrower character set. The repository explicitly warns that unsupported input, including hyphens in its example, is silently dropped. Callers should surface that limitation before encoding rather than assume every mode preserves every string.
The documented GIF is a small reproducible output, not a benchmark of the entire library. Runtime performance, reader compatibility, and handling of unusual inputs should be evaluated separately.
Preserve the payload
A barcode is often the boundary between physical inventory and a software record. Choosing an encoding is therefore a data-integrity decision, not simply a rendering preference. Inspecting the input, codewords, and generated image together makes it easier to see where a payload changed and which layer should reject an unsupported character.