I've commissioned images from an artist, which all images have been delivered in PSD and PNG formats.
As a Linux user, PSD files don't open well on software like GIMP and ImageMagick due to the issues with clipping masks, plus I'd like to avoid a proprietary format if possible regardless as these will be going on a public project on GitLab.
What are the best image (or project) formats that support layers? It's preferred if it's widely supported, but if it at least works with GIMP and ImageMagick, that'd be good enough since a script will automatically export it to more conventional formats like PNG.
I've tried looking at many standard ones however they don't support layers, TIFF I learned isn't completely open which is why even though Photoshop supports layered TIFs other programs can't open each layer, EXR doesn't have good support it seems between what Photoshop exports when GIMP imports it.
Edit: Small addendum, I've now looked into OpenRaster (.ora), however it appears ImageMagick does not support it unfortunately.