I have a folder with 350 GIMP XCF files. Each file is a single transparent layer (102 × 290 pixels) with a simple drawing (a line).

I would like to merge all the 350 files into a single file to visually represent all the 350 lines combined.

I have tried the following command, but it doesn’t seem right.

magick *.xcf -compose Divide -composite combined.png

I don’t think outputting as a xcf file is possible since I get the following error when I use combined.xcf:

magick: no encode delegate for this image format `XCF’ @ warning/constitute.c/WriteImage/1400.

magick: no encode delegate for this image format `XCF’ @ error/constitute.c/WriteImage/1409.

I would be most grateful if you can advise how I could combine these 350 files automatically.

Many thanks