and new studies also depend on both. Therefore, we suggest complementing the FAIR (meta)data principles with a concept for materials that address sustainable access to and re-use of physical objects such as chemical samples wherever possible. The concept should make it possible to secure physical research results, verify the gained results and increase the re-usability of the materials in addition to the re-use of already well-established data. To this aim, chemical compounds or more precisely samples of chemical compoundswhich are the starting point of analytical studies or the outcome of synthetic studies in chemistryshould be preserved and made available. As a first step, the metadata of samples would need to be Findable, Accessible, Interoperable, and Reusable (= FAIR metadata for samples). In the second step, the samples would need to be registered and stored in a materials archive to be Accessible, and made available under suitable access policies and rules to be physically Reusable (= AR material for samples). This concept is further referred to as the FAIR-AR samples concept (Figure ). The FAIR-AR sample concept in detail. Metadata for a sample can be seen as a virtual representation of the sample or in other words a digital object to which a globally unique and persistent identifier can be assigned. Metadata that are part of such a virtual sample representation include information on the sample's provenance, components/content, and properties. Most of the metadata assigned to such a virtual sample representation are relevant for a FAIR data approach if it comes to a comprehensive description of analytical measurements of chemical samples. This is because chemistry samples can usually be described with standardized metadata, to which both, the physical sample and the gained data refer. Efficient concepts that intend to consider the FAIR deposition of research data and the deposit of FAIR-AR samples could, therefore, closely link research data deposition to sample deposition. A design to this is depicted in Figure , showing a virtual sample representation described by rich standardized metadata, which is complemented by (1) information on further relevant data assigned to the sample (Figure , left), and (2) information on available samples' location and its unique registry or reference number (Figure , right). The information on the samples' location must come from the registration of samples made available via an archive for materials. A standardized process for the stockpiling of the samples, with a suitable validation of the materials and mechanisms to assign unique identifiers, is needed to gain such a deposition and registration of samples. Further, it means that the delivery and samplesharing process (if applicable) is well described and standardized, including rules that might control access to the materials. Therefore, a sustainable materials approach should include information on the usage conditions of samples, such as legal agreements, and if available safety information.