Created in Blender 2.79b. A set of four pieces of firewood. Totally individually textured with photographic image textures. With roughness, height and normal maps applied.

 The bark and inner wood are separate objects parented to an empty to make then easy to move, scale, etc. Also the bark can reveal more inner wood by going into edit mode and deleting face. This allows for a great deal of ability to make different objects.