Methods are disclosed for converting on a mass scale elongated material webs into finished parts or devices. Slits form strands in a web, the strands comprising interconnected objects which correspond to parts of finished devices. Strands are combined with additional webs to form a material laminate from which finished devices are die cut. The methods are suitable for a range of converting applications including medical devices, particularly the external nasal dilator. Complex dilator devices produced from the methods are formed as a single body truss having horizontal regions adapted to engage outer wall tissues of first and second nasal passages of a nose. When in use the dilator stabilizes or expands nasal outer wall tissues and prevents the outer wall tissues from drawing inward during breathing. Methods of manufacture comprise separate steps for fabricating and assembling the elements and layers of finished dilator devices and for packaging finished devices individually or in groups. Waste material is incorporated into subsequent fabrication processes to produce the same or complementary devices.