How it works...

Unity is able to read four channels of a texture map: R (Red), G (Green), B (Blue), and A (Alpha). When set to Transparent or Cutout, the Alpha Channel of the diffuse texture map sets the transparency of the material according to each pixel's brightness level (the Cutout mode will not render semi-transparency – only fully visible or invisible pixels).

We didn't add an Alpha Channel – this is because Photoshop exports the PNG's Alpha map based on its transparency. To help you visualize the Alpha map, the provided folder also contains the package_diffuse.tif (TIF format) Texture file; an image file featuring an Alpha map that works in exactly the same way as the PNG file that we have generated:

Regarding the Emission texture map, Unity assigns its RGB colors to the Material, combining them with the appropriate color selection slot, and allows adjustments to the intensity of that Emission.