Type-level taxonomy separates allograft-derived matrices from heterologous collagen membranes, each with distinct reimbursement and regulatory profiles. Allograft dura (cryopreserved or lyophilised) historically led adoption due to histological similarity, yet processing costs and prion-related safety concerns have flattened growth. Conversely, bovine pericardium grafts, cross-linked to slow resorption, now hold the largest revenue position because of scalable supply and proven tensile strength. Porcine small-intestinal submucosa (SIS) follows, positioned as remodelable and infection-resistant, capturing share in paediatrics and revision cases. Emerging recombinant human collagen sheets, though nascent, command premium pricing where immunogenicity must be minimised, completing the market taxonomy and setting the stage for future biological dura substitute substitution patterns.