Minor correction I think many of the first season episodes are still using construction paper. You can occasionally see their hands appear in frames.
But yeah after the early episodes / seasons it's cgi
But yeah after the early episodes / seasons it's cgi
Thanks for clarifying, good point. I should've been more clear in my original comment, because I meant to say that the pilot used real construction paper only (with no CGI), not that construction paper wasn't used at all after that.