Blender does not save the image, which you are texture painting on, automatically. You have to save that image on your own manually.

That's why there is this * on image, to indicate, that it is not saved.

If you close Blender without saving the image, it is lost.

Blender does not save the image, which you are texture painting on, automatically. You have to save that image on your own manually.

That's why there is this * on image, to indicate, that it is not saved.

If you close Blender without saving the image, it is lost.

check here for details:

https://all3dp.com/2/blender-texture-painting-simply-explained/#:~:text=Save%20the%20image%20file.,a%20destination%20on%20your%20computer.