The stamper is then installed in the CD/DVD molding machine. A DVD disc consists of two polycarbonate substrates bonded together. To create each substrate, molten polycarbonate resis is injected into the DVD molds and compressed against the stamper. The resin replicates the layer bumps. The molded substrates are now an exact copy of the original master. After molding, the substrates are then metalized with a reflective coating deposited onto the encoded surface of the substrate.
In the case of single-sided, single layer DVD5 discs, the aluminum metalized substrate is bonded to an additional blank substrate as the top layer. For a single-sided, dual-layer DVD 9 discs, a semi-reflective substrate is bonded to a fully reflective aluminum substrate on the top. For double-sided, single layer DVD 10 discs, two metalized layers are created and bonded.