His micro-fusion process of pressing records required each mold be filled individually by people in a production line. The mold was then passed to someone at a record press. Cook thought it would be better for record stores to press records themselves, as they were requested by customers, rather than pay shipping and stocking fees. By 1958 there were record stores on Caribbean islands from Puerto Rico to Trinidad that had a Cook record-press in the back. Some stores began recording music. They shipped the master tape recording of an album to Cook, who made a metal mold of it and then returned it to the store. When a copy of a record was requested, the mold was filled with powdered vinyl and then placed a high-pressure press.