The IUCr Executive Committee has charged a Working Group with an assessment of the potential benefits of depositing raw experimental data sets (with initial emphasis on X-ray diffraction images), and the cost, technical and structural ramifications of doing so. There are a number of potential locations for depositing raw images that allow their reuse in validation, re-refinements, reanalysis for new science, education and software development - for example, in discipline-specific data centres, in large-scale instrument facilities, or in institutional repositories. These are not necessarily exclusive (for example, a central data centre might archive only data sets associated with published structures), and initiatives such as the Australian TARDIS demonstrate approaches to federating separate repository platforms. Crucial to interoperability between such federated archives will be well-defined metadata and procedural standards.