In regulated financial services, semi-structured payloads such as XML, JSON, PDFs, and messages are not “raw data” to be discarded after parsing: they are primary evidence. This article argues that blobs must be treated as first-class artefacts: preserved intact, timestamped, queryable, and reinterpretable over time. Relational models are interpretations that evolve; original payloads anchor truth. Platforms that discard or mutate artefacts optimise for neatness today at the cost of defensibility tomorrow.