Dunlop and Talalay refer to the process by which liquid latex is transformed into sheets of latex foam.
Both Dunlop and Latex processes begin and end similarly. Latex foam is made from a concentrated liquid latex rubber that has been harvested from the rubber tree. The liquid is whipped to incorporate air and poured into latex sheet molds and baked in a special oven where vulcanization takes place. Vulcanization happens when tiny amounts of sulfur are introduced into the latex serum, which creates a reaction that generates three-dimensional network structures in rubber and is the best-known process of giving rubber products greater stability.
Through Dunlop process, the molds are filled all the way to the top prior to baking. The newly vulcanized sheets of latex foam are left to air-dry before baking one last time to remove all moisture. During the time of air-drying, particles tend to settle toward the bottom, making a slightly uneven distribution of density. This can affect how soft or firm your latex topper feels. Dunlop latex mattress toppers tend to be ever so slightly more durable, firm and springy than Talalay.
Through the Talalay process, the molds are not filled all the way to the top, rather they are vacuum sealed after partial filling to evenly distribute the latex particles. After the vulcanization process, the latex foam sheets are rapidly cooled to prevent any settling. This process creates a latex foam sheet that is uniform throughout, creating a slightly less-dense, but generally overall more plush-feeling surface. Talalay will have slightly less spring to it, enveloping your body a little more than the Dunlop. Because the Talalay process involves more steps and is slightly more complex, it tends to sell at a higher price than Dunlop.
If you tend to prefer a more plush (soft) feeling for your sleeping surface, we recommend choosing Talalay, regardless of the firmness you choose. If you are looking for extra support, we typically recommend the Dunlop option. Regardless of which you choose, both process produce latex that is far more durable and comfortable over its usable life than any other topper material.