A method of providing an article having a set of directional channels, including a first directional channel, therein is described. The method comprises preparing a mixture including particles comprising a first material and a first binding agent. The method comprises providing an article precursor by surrounding a pattern comprising a second material with the mixture. The method comprises heating the article precursor thereby coalescing the particles to provide the article. The method comprises removing the pattern by reacting the second material to form a gaseous product, thereby providing the set of directional channels in the article, wherein the set of directional channels corresponds with the removed pattern. Such an article is also described.