how to make a proper texture

Hello, I am new to UR and I want to make a texture (inside PS) for wood floor. According to this
tutorial https://docs.unrealengine.com/latest/INT/Videos/PLZlv_N0_O1gbQjgY0nDwZNYe_N8IcYWS-/sIMmDVLqh1s/index.html
I need a texture whit alpha. I try to save png whit alpha but in UR I dont see the alpha. Can someone pls help how to make a proper bitmap file whit all information i need? Thank You.

For PNG the alpha is transparency, if you need transparency in the material then that’s OK, otherwise if you’re trying to put a roughness map in the alpha channel you would need to use a different format like TGA where it won’t treat the alpha as transparency.

Photoshop is weird when it comes to saving alpha channels out. If you ‘save for web’ instead, it should work. Otherwise, as Darthviper says, use .tga instead