Bump maps have a tendency to blend without being blocked by the image above. They work slightly differently then color maps but that wont effect what we are doing here. There are some things to remember when making adjacent surfaces seamless. The most obvious, you must match color for color on adjacent surfaces. And, if you take a look at the side face surface you will see that all of the maps and basic material properties have been matched with the properties of the front face texture.
All values are the same.
Or, the maps that are used in the texture areas are seamless. If you have a rendering problem and you have paid close attention to color differences between adjacent maps, I ll bet ya ten to one that there is a spinner somewhere with a different value then the adjacent surface. You just need to find it. Take as our last example, the top of his head. No wrinkles or colors to worry about.