The document discusses PVA (polyvinyl alcohol), a biodegradable, water-soluble polymer used in 3D printing, especially as a support material for complex geometries. It outlines the advantages and disadvantages of PVA, printing conditions, and practical tips for successful use, such as maintaining dryness and using dual-extrusion setups. Lastly, it emphasizes the effective application of PVA for high-quality printing results.