A childhood belief about cartoons

I very early found out that cartoons are in fact series of fast changing pictures, each next only a bit different from previous. It was well explained in some magazine for kids. So I knew how does every cartoon work, but I though it is executed just like the cartoon-book you can make yourself - they are holding out there in the studio thick stack of colored papers right in front of camera, and when the sheets are moving very fast, it is just being filmed and showed on TV. So many times I just wondered why all those cartoons on TV are so perfect quality since there should be visible trails of sheets moves etc. Then some day I found out they just record each one picture in the other film-tape tile, and this is it.