Supramolecular architectures, based on synthetic peptides or DNA, are the essence of modern bionanotechnology. Carbohydrates, the most abundant biopolymers in Nature tend to form hierarchical architectures. Limited access to pure and well-defined carbohydrates hampered the molecular level understanding of polysaccharides, preventing the production of tailor-made materials. Automated Glycan Assembly produces now well-defined natural and unnatural oligosaccharides for detailed structural characterization. Defined glycans can assemble into supramolecular materials with different morphologies, depending on their chemical structure. Here, we describe how synthetic oligo- and polysaccharides help to establish structure–property correlations to guide the development of novel polysaccharide materials.