if you look at an animation like The Princess and the Frog. the outline of the characters are very thin. when i draw with the thin pencil 2, there are gaps in between the line that i have just drawn. is there any other way to do it? thanks!

What do you mean by gaps?

Small ones you can’t see or big gaps visually?

sort of both

well a pencil line should always be the same thickness so i don’t know why there would be visual gaps.

You can close the small gaps you can’t see with the close gaps tool in the paint flyout.

Also when drawing with the pencil tool you can turn auto flatten and auto close gaps (in the tool properties) and that might help.