So basically when setting up a screen printing job that requires black ink on a white shirt, you can use the wrong screen mesh, have no off contact, and print with the completely wrong squeegee technique and still get an OK looking final print. However, if these same wrong techniques are tried when printing white ink, uh oh, game over! The unfortunate thing is, many printers start out this way and teach themselves completely wrong. In fact, this is how I learned. It's not the end of the world though!