An example of a door curtain having pieces comprised of different thermoplastic materials includes a weld medium that facilitates the welding of two thermoplastics that are otherwise not readily welded together. In some examples, the weld medium comprises two outer layers that are joined to each other, wherein one layer is of the same polymer as one of the curtain pieces, and the other opposite layer is made of the same polymeric material as that of the other curtain piece. The weld medium is sandwiched between the two curtain pieces such that matching materials of the curtain and weld medium face each other. The two curtain pieces, with the weld medium between the two, are then thermally or ultrasonically welded together. The weld medium can be made by coating a fabric sheet with the two different plastic layers bonded to opposite sides of the fabric sheet.