I'm making a texture of a simple glowing orb on a transparent background. When I have everything looking good in the initial window exporting it to .png format leads to a loss of colour and detail, despite using all manner of export options in all manner of combinations (save colour profile, save gamma, etc. etc.)

You can see the difference in the supplied image: what comes out is extremely different. The black background is not part of the original image, I've just added it here for ease of comparison.

I've also enclosed a Google Drive link to the initial .xcf and the resulting .png in case examining them helps.

I'd really appreciate some help solving this because I'm rather frustrated!

enter image description here

Files: https://drive.google.com/drive/folders/1oF0RkuDBbQ_I21i_IDewCuxMPIvZEojw?usp=share_link

1 Answer 1


The image is set to 32bit floating point precision. The PNG format doesn't support that. The maximum is 16bits per channel. (64 bits in total for RGBA).

It's going to be difficult to get it down to 16 bits per channel now. Conversion will make it look dull. It would have been better to design this at that 16 bit, then you wouldn't have had that problem.

A possible method might be to add a black background layer, merge the layers, convert to 16bit, then use the Color to Alpha filter to remove the black.

It kind of works

enter image description here

  • I see, it seems I've misunderstood formats/precision modes. I had watched something which suggested to always use 32bit for best quality and results, but it seems that won't work exporting to PNG. Funnily enough, I did try the black background business, and was about to post a comment outlining that it worked to a degree, but that I did not understand how or why. It seems that will have to suffice, or I just export to a format which will support 32bit/design in a different precision mode from the outset. Thank you for your response.
    – Smith
    Feb 9, 2023 at 21:42
  • @Smith - there are formats that support high precision, but PNG is for the web. There is no browser that will display images with such bit depths.
    – Billy Kerr
    Feb 9, 2023 at 21:45
  • If you don't mind indulging me a little more, do you happen to know just why it is that merging with a black background and then colouring to alpha/colour erasing the black seems to preserve some of the colour?
    – Smith
    Feb 9, 2023 at 21:51
  • Because you are basically baking in the pixels as 100%, no alpha. Then when you convert to 16bit, most of the colours will remain. Suffice to say, extremely high precision images are not really optimal for the web, it's kind of for specialist image processing most ordinary people will never need. Work at 16bit. The human eye likely won't see the difference anyway.
    – Billy Kerr
    Feb 9, 2023 at 21:52

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