Bast fibres have been critical materials in the evolution of human civilizations. In particular, their use in fishing technology for nets, traps, or lines-- as well as in maritime transport --for ropes, sails, and sailors' clothing, have enabled mobility, livelihoods, and the exchange of goods and transmission of cultures since pre-industrial societies. Here, we propose a range of results obtained from two groups of ancient samples: i. Well-preserved fishing nets from two distant but contemporaneous groups at the end of the 4th millennium BCE: one from Neolithic period in Egypt (Neolithic period, ca. 5265 ± 30 BP) and the other from the Middle Preceramic Peruvian Pacific coast (5350 ± 30 BP). . The fishing nets possess substantially similar textile architectures even though they use bast fibres from different species: Linum usitatissimum L. (flax) by the Ancient Egyptians and Asclepias sp. (milkweed) by the coastal Andean community. ii. Egyptian Linum usitatissimum L. (flax) textiles originating from different periods and having different functions: one mortuary linen dating from the early Middle Kingdom (Eleventh Dynasty, ca. 4056–3986 BP), one other textile used for mummy stuffing (Old Kingdom, ca. 4481-4232 BP) and one figurine garment, found in ancient galena mines at the Geb-El-Zeit site (Second Intermediate Period,; ca. 3630-3474 BP). We examine these different fibre types and studied their distinct processing, morphological and ultrastructural characteristics. Multi-photon and scanning electron microscopy (SEM) are supplemented by 3D micro-computed X-ray phase-contrast tomography to investigate the unique architectures of the yarns and their individual fibres artefacts. These ultrastructural characteristics are discussed in relation to the mechanical performance of the fibre cell walls measured by atomic force microscopy. We demonstrate the use of state-of-the-art micro-spectroscopy techniques for archaeobotanical studies, and use these ancient artefacts as a new lens to unravel the episteme and techne of fibre and textile production in the past, but also to better understand the durability and ageing of plant fibres.