• Auto mode → [5-digit prefix] + [sequence]. Sequence is zero-padded to 4 digits up to 9999 (e.g., 0001…9999), then grows naturally (10000, 10001, …).
• Encodes as Code 128 (Set B) with automatic checksum. Printing is true-size to your mm settings.
Preview auto-scales to fit your screen. Printing is true-size.