Brandished by everyone from grade schoolers to cops, chalk is the ideal temporary marker. Here are some tips for multitasking with the powdery staple.

1. File Right. Rubbing chalk onto a metal file makes its teeth easier to clean by reducing their tendency to clog with soft metals.

2. Degrease a Collar. Rub the spot with white chalk, let it sit, then dust it off.

3. Locate a Box. When installing drywall, This Old House general contractor Tom Silva rubs chalk on the front edges of electrical boxes. After positioning a sheet of drywall, then pressing it against the box, he can cut neatly along the transferred outline.

4. Repeat Patterns. Chalk, sanded into a powder, helps woodcarvers repeat a design. Attach a perforated stencil to the workpiece, then sprinkle the dust over its holes to create the pattern.

5. Adjust a Strike Zone. When deadbolt latches don't quite fit, TOH contributor Larry LeMasters marks the end of the bolt with chalk to leave a record of contact on the strike plate. Then he enlarges the plate's opening with a file until the bolt fits.

6. Track a Walk. Landscape contractors organize complex flagstone layouts by chalking numbers or letters on the stones.

7. Patch a Wall. To fix odd-shaped holes in plaster, TOH building technology editor Tom Baker rubs the outline onto paper with chalk. The impression makes an accurate template for cutting metal reinforcing lath.

8. Plan a Room. Because it easily erases, TOH technical editor Mark Powers uses chalk to mark locations of fixtures and partitions right on the walls and floor before committing to a final remodeling plan.

9. Cinch a Screw. Scraping both sides of a flat screwdriver on a piece of chalk keeps it from slipping off the screw as you tighten it.

10. Sand Evenly. When matching a seam, rub chalk along it. Chalk on a high spot will disappear first. Stop when all chalk is gone.