Errors and floor sweepings are NOT the same things.

"Error chips" are chips that were meant as a regular run, but something went wrong. Many times they made their way into the racks.

"Floor Sweepings" were junk chips that were just used to prime the hot stamping machine, or some other test. They were never meant to be a legitimate chip. Think of it like that scrap of paper on your desk that you scribble on to prime your pen before actually writing something.

Many floor sweepings are struck many times, and by different stamps, because they were sitting around when it was time to start. The term "floor sweeping" was because it was assumed they were tossed on the factory floor and swept up with the other trash.