Coextruded articles, dies and methods of making the same

A coextruded article comprising first and second layers each having first and second opposed major surfaces and between the first and second layers a series of first walls providing a series of microchannels, wherein there are at least 5 first walls per centimeter, wherein each wall has a height extending from the first layer to the second layer, wherein for each wall there is a first average width along the first 2 percent of the height of the wall, wherein for each wall there is a second average width along the last 2 percent of the height of the wall, wherein for each wall there is a third average width along the remaining 96 percent of the height of the wall, and wherein for at least 50 percent by number of the walls, the first average widths are less than the third average widths and the second average widths are less than the third average widths;

• wherein the first 2 percent of the height of the wall extends from the first layer toward a middle of the wall, the last 2 percent of the height of the wall extends from the second layer toward a middle of the wall, and the remaining 96 percent of the height of the wall extends from the first 2% to the last 2% of the height of the wall.