D. Finding the Magnetic Field Using Iron Filings 9. Place a blank piece of paper on top of the cardboard. Place these both over the bar magnet laid flat on the tabletop. 10. Sprinkle a small amount of iron filings lightly over the top of the paper. Try to evenly coat the paper with a fine layer of iron filings. Tap the cardboard lightly until a pattern appears. Sketch this pattern on the diagram provided below