• Tedious to specify texture coordinates for every triangle
• Textures are attached to the geometry
• Easier to model variations in reflectance than illumination
• Can't use just any image as a label texture
  The "texture" can't have projective distortions
  Reminder: linear interpolation in image space is not equivalent to linear interpolation in 3-space (This is why we need "perspective-correct" texturing).
  The converse is also true.
• Textures are attached to the geometry
• Easier to model variations in reflectance than illumination
• Makes it hard to use pictures as textures