When exporting a painting, a generationname is saved to the .paint file.
I suspect that the saved generationname is copied to the canvas upon importing, and this results in some strange effects when it's used to clone a painting.

The edited painting will either:

• Modify the original painting used to export that image (And any other paintings that have the same generationname).
• Be reverted to match the original painting upon placing the canvas. (In this instance, your changes to the painting will not be shown in the inventory icon

Steps to reproduce:

1. Create a painting
2. Export the unsigned painting
3. Import the painting onto a blank canvas
4. Edit this imported canvas.

Fix for users experiencing this issue:
Before importing, edit the .paint file and change the generationname preceding ctpixels in some way (change a digit or two, for example)