Very new to Pencil2D-backgrounds question

Hi, am a total beginner, but working my way through the video tutorials. One thing I can’t find is: how to change to a different background after a few frames. I uploaded a new background after a few frames, but when I do, the background changes in all the frames. Thanks

Depends on how you are doing your background. Typically you will create one background layer at the bottom of your project. On the first frame you put a keyframe with the first background you want to use. This frame will automatically be held/exposed on all frames after it that are empty (ie. don’t have a keyframe) on that layer. If you want to change the background at a certain point, you need to create a keyframe at that position, and then you can draw or do whatever you want on that frame and it will affect all empty frames after it.

If you draw in a position without a keyframe, it may end up drawing on the previous keyframe, which will modify all frames if you only have one keyframe at the beginning. This sounds like this issue you are having. The solution is as described above, manually create a new keyframe with the new keyframe or duplicate keyframe buttons at the top of the timeline before doing modifications. Alternatively you can change this behavior to automatically create a new keyframe in the preferences, but this should not be solely relied upon.