My question is simple: does Blender support texture where RGB is color, and A is a grayscale texture (not transparency)?

The image file can be PNG or TGA, both with straight (aka unassociated) alpha, and all I want is to extract that alpha, without affecting the color channels.

So far, I have tried every "color space" + "use alpha" setting combination, and none can give me both a straight alpha and correct RGB color:

  • I can pick sRGB/Linear without alpha, then I got RGB channel right, but A channel is all white.
  • I can pick sRGB/Linear/Non-color/Raw with alpha, then I got A channel right, but all black in RGB channel.

And this only affects Render view. Material view is somehow happy either way.

Any clues?

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  • $\begingroup$ similar question was asked here, in 2015, but I should note that I already know this workaround: it basically require you to duplicate the texture file, as color-space and use-alpha setting are per texture, not per image node. blender.stackexchange.com/questions/32450/… $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 8:23
  • $\begingroup$ other workaround (such as dividing alpha) is not possible here because alpha is 0. and so far I research suggest texture with non-transparency alpha are still unsupported as of blender 2.79 releases $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 8:24
  • $\begingroup$ my case is also the opposite of this question: where OP wants to apply the alpha mask, which is do-able in Blender. blender.stackexchange.com/questions/104642/… $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 8:27

1 Answer 1


This behaviour seems to be internal, so no easy way to modify it. But a way to facilitate that duplication process is to instead of duplicating the texture file itself, duplicating the Image datablock that references the file inside Blender.

  • Create the Image Texture node as usual and duplicate it, and then click the user number to make a new copy of the Image datablock -- they will both reference the same file but have separate Use Alpha settings.

Click to make a single-user copy

  • $\begingroup$ Cheers, I am aware of this though: see my comment in OP :) $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 10:49
  • $\begingroup$ You wrote "duplicate the texture file" in the comment, to me that means a file in your HDD. To clarify: image file = file.png | image datablock = image object as seen in the UV\Image Editor | image texture node = cycles node in the node editor. You duplicate the image datablock ("make single-user copy"), not the file. $\endgroup$
    – R. Navega
    Commented Aug 13, 2018 at 12:32
  • $\begingroup$ @RN thx for clarifying, I should have edited that comment, I am aware of both approaches. $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 13:15
  • $\begingroup$ (for future users: this is what we are talking about, select image texture node, press N in node editor to view properties panel and find this: i.sstatic.net/zPKfA.png ), one thing I don't quite like about this workaround: it's quite easy to have used an incorrect source image file as there is no way to view them without expanding properties view. $\endgroup$
    – bitinn
    Commented Aug 13, 2018 at 13:25

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