Texel density refers to how many pixels on our texture map are dedicated to each area of our UV islands. It's another way to think about distortion in our UVs; if our UVs don't have even texel density, then we will get distortion.
We want our UV islands to have even texel density as often as possible, especially for important areas of the character, such as the head. The claw was very problematic and easy to notice since it was a big gray blob, but the baby dragon's head is also problematic. The texel density changes from the forehead to the snout to the jaw:
Texel density issues on the baby dragon's head
These ...
