How will we know if the unwrapped faces aren't stretched or deformed by the process? To determine this, we use something called a test grid. It's an automated image that can be created by Blender in the UV/Image Editor window to show us how the texture is distributed over the object's surface.
To create a test grid, just press the Alt+N keys in the UV/Image Editor when a model is unwrapped. This short cut creates a new image based on some information provided in a small menu. In this menu, we can set the image to be a UV test grid by pressing the UV Test Grid button. In addition, increase the size of the image in order to produce a high quality image. For this example, the images were set to Width of 2056 pixels and a Height of 2056 pixels.
The test grid will look like an image full of small squares painted gray with small marks at the center of each square. Notice that these squares and the colors in their centers are only indented to help the visualization of the UV layout...
