I went ahead and continued with the next tutorial, where I am starting now to learn about shading and rendering. That gave me the idea to come back here and fiddle around with the render settings. I don’t really know what I am doing yet, but I found a combination that made the texture show up in Sketchfab. I switched to Blender Render, and then found a way to select the ax and add a texture to it in the Properties panel. Someday when I understand better it will probably be obvious what I was doing wrong here, but just at the moment it is all a bit mysterious.
