This texture can temporarily replace one of your seamless textures for applying, mapping materials such as wood, concrete, etc. . It roughly shows the user roughly the scale and orientation that their finished materials will have–just by looking at it. When you are done, the original material may be swapped back.
The 2048x2048 texture can be either resized, or cropped to suit your needs.
Yes consider: [UVEditor TIP] UV mapping: Replace your UV Grid Texture
Put to the right and bottom edge a white outline into the texture. This will help you to define when you are out of the UV space. Also consider adding circles in each small square.