See, if that's the case, then SetBlend MaskBlend will use it in this way.
Yeah, I wasn't sure about that, so I left it at 3.
I think maybe in AlphaBlend you don't have to do SetAlpha at all, as it takes the alpha value from the alpha channel?
No, in such a case, the alpha value from the alpha channel is "multiplied" by the alpha you set in SetAlpha. Besides, you don't have to use an image with an alpha channel to use AlphaBlend.