Once processed, latex is poured into molds and vulcanized (treated and heated) to create three-dimensional foam. There are two different processes to turn liquid latex into the foam, which is used to make latex mattresses - dunlop and talalay. Both methods produce high quality mattress foams varying in density and feel.
The older, simpler method is known as Dunlop, where liquid latex is slowly poured into mold layer by layer, where it is allowed to set and harden, and later is vulcanized. Dunlop latex is generally more dense, heavier and firmer and therefor is mainly used in a mattress core. It will hold the shape of the mattress better over time and will be less likely to sag or develop body indentations.
The newer, more sophisticated and more expensive method is known as Talalay, where liquid latex is poured to the mold with extra room left on the top. Mold is then sealed and air is vacuumed out of the mold, so the foam will expand and fill entire mold. In the next step the mold is instantly frozen, so the foam keeps its shape, and vulcanized. Talalay latex tends to be softer, more porous and less dense. It is preferred for use in top comfort layers providing better pressure relief.