Before records can be made, first we'll need to make the molds that will be fitted to the press dies. Your lacquer masters have a copper backing which is our cathode. The surface of the grooves is first coated with thin layer of silver. Then it's attached to one of the yellow rotating discs pictured above. The bath is set to an operating temperature, and nickel pellets are loaded into distribution trays and used as our anode. The nickel is dissolved into the bath as nickel ions. When an electrical current is introduced the ions are attracted to the copper cathode and will create a thin layer deposit. After about an hour in the bath the freshly plated lacquers are pulled, dried and then separated. The lacquers are no longer of any use but the information they contained is now transfered onto the first plate called the Father. Lacquer masters are a positive image, the Father is now a negative. In a one step process the Father would be centered, trimmed, formed then used in the press. Though it can save time and materials, the Father is the only copy of your programming, so if it's damaged a new lacquer master will need to be created. This is the reason why we do not offer and recommend one step plating. With two and three step processes the father goes through a similar operation to the lacquer master. Its placed in to the bath to create Mother and Stamper plates. Mother plates are key to quality control. Should there be an issue with either the Father or stamper plates, new copies can be made.
Plating is just one of many steps before we have molds ready to be mounted for pressing. Stampers will first need to be centered. This is done using a specific cutting tool that requires a micro scope. If stampers are off center your records won't track properly or will worble during playback. After the centers are punched they must be crimped and the outside edges coined. Ultimately the form is specific to the presses dies, so they fit like a glove and can be secured flat and tight. Oddly enough because die designs and press makes vary from each pressing plant. Once a stamper has been formed, it is unlikely you'll be able to use those plates elsewhere.
Plating plays a key role in the quality of a vinyl record. Common issues with test copies are rarely pressing related, and can be traced back to either the original lacquer or one of the plates. A piece of hair or dust will manifest into a skip or a pop. At every pre-press stage there is an opportunity for contamination or damage. Though parts are treated as such, it is always wise to order test pressings. Essentially the entire purpose is to ensure the quality of the molds, not the quality of the pressing. Pressing issues can be resolved in your production run, however issues with your plates can not.