Gimp copy paste between layers

I have a 256×256 image with multiple named layers to make it easy to edit game graphics that have transparency as PNG. I want to paste the contents of one layer to the next… so I select the source layer and use Shift-click to make all others invisible, then press Ctrl+C, I then go to the next layer up Shift-click and then paste – but it inserts a “floating layer”, I’m misunderstanding something basic here.

Image Batch Processing: Remove horizontal slice of an image and fill its void by the surrounding areas from above and/or below

Original Images & Desired Outcome I have a batch of PNG images which need the same automated image processing: Middle part (red) shall get eliminated entirely and its void filled from above/below Top (blue) and middle part (red) always have the same height The bottom part (green) may vary in height How do I achieve … Read more