Ohhh i sometimes do that!
I tought there was some kind of frame layering lol

I mean when you make another frame, the sketch turns into an onion skin and then you can make line art without going through the pain of all that erasing

You mean the background layer?

Layer?
Woah i didnt knew anime maker had layers! (After 4 years lol)

I just do the line art on another layer and then delete the sketch layer