Thread:StarryTheZodiacQueen/@comment-32460917-20180429034059/@comment-32460917-20180629063906

I,,, didn't check the user guide

I usually use the paint bucket tool and then scan over the filled areas and check for any empty spots

There's an option for the bucket where it can "refer to other layers" so as long as your lineart has closed spaces, you should be able to fill them on a separate layer no problem