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Not compatible because the default layer mode contains new options.



Change each layer to legacy for backward compatibility.



Looks like all your layers are 'normal' mode so should not make any difference to the image...but going to be tedious changing them now

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Very interesting, thanks for the preview-review. good to see things happening on the GiMP front! Nice artwork too.
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Griatch

Good work as always Zeo. I have stuck with 2.6 for various reasons. For a painter, it is just so much easier than later versions. With 2.10 did you try disabling colour management in preferences?

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Could the lag in the brush be a result of using an appimage vs fully installed version? I would think using an appimage would use more system resources since it runs on a virtual drive and thus uses more memory.

That said, my Gimp 2.10 appimage runs very well and is super stable, though I rarely ever use a brush. One thing I'm not, is a painter...

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It all depends on how much RAM you have. The more RAM, the better.

Here is a test. 4000x4000 image, duplicated 15 times, Airbrush @ 320 px. It has some lag, but not too bad.

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Well stick with v2.6 for your painting then. I don't paint, so have no issues with the brush on the very rare occasions I use it. You may want to pick up a 2.6 appimage if you can find one. Just in case your future OS version doesn't support the installation of v2.6.