I have modelled many things in blender and imported them into Unity, but have never come across this.
The box I have modelled is white with a logo and text, on each side, and the top. The .png I have used for the base of the box looks like this
When I place the box into the scene it turns out like this
I have tried re-importing the textures, the whole box and have tried a lot of the different settings one at a time where I think it may have some effect, but I believe now that this is an aberration. When I set the ‘Rendering Mode’ on the Shader to transparent, cutout or fade I can adjust the alpha channel in the colour picker and it looks like a see-through box with the logo and text displayed correctly. This would be great if only I wanted a see-through box with floaty labels.
Any help would be greatly appreciated.