The writers had considered developing Bernard and Bianca into married professional detectives, though they decided that leaving the characters as unmarried novices was more romantic [REF].
Ever since One Hundred and One Dalmatians, animation for theatrical Disney animated films was done by xerography, which had been only been able to produce black outlines, had been improved for the cel artists to use a medium-grey toner in order to create a softer-looking line [REF].