The European silk heritage is an integral heritage that encompasses both tangible properties (looms, fabrics, threads, etc.) and an important linguistic intangible heritage. Its importance as a heritage is undoubted, but although silk has woven Europe and is still used in numerous contexts, traditional weaving is at risk due to the gradual loss of the artisans that safeguard the ancestral knowledge associated to it. Moreover, silk remains relevant to people who experience living, personal and social connections with this heritage, which is linked to so many life stories and collective narratives that it has generated a specific vocabulary. The way in which silk-related properties have been catalogued is very heterogeneous due to the lack of standardisation of the catalogues of the museums that hold them. As a result, the vocabulary of silk heritage comes from multiple sources that have been mixed over time and space, resulting in the interoperability of this data and catalogues being extremely complicated. To address these challenges, the SILKNOW project took on the challenge of creating a multilingual thesaurus that is the basis for other project tools, standardises the vocabulary of silk weaving, and rescues the intangible heritage associated with it. This paper presents the rationale behind the creation of this thesaurus and its relationship with the safeguarding of tangible and, above all, intangible heritage.