A method of manufacturing a flexible, impact-resistant material (1) comprises the steps of providing a sheet of a closed-cell foam material (20) and cutting the sheet (20) into a plurality of spaced elements (2). These elements (2) are substantially separated except for connecting portions (7) that connect the elements to neighboring elements such that the elements (2) are joined to define a lattice (6). A first flexible substrate (3; 25) is bonded to one face of the lattice. The connecting portions (7) that connect the elements (2) to neighboring elements are then removed, either with or without removing those portions of the substrate (3) bonded to the connecting portions (7), for example by punching, cutting or laser ablation. A second flexible substrate (27) may be bonded to the opposite face of the lattice either before or after removal of the connecting portions.