Marco was a new homeowner, proud of his fixer-upper Victorian. The house had charm—original woodwork, stained glass, and thick marble windowsills in every room. But the marble in the kitchen was a blotchy, dated beige with a few dark stains from decades of coffee mugs and potted plants.

“Can you just paint them?” his wife, Elena, asked. “White gloss. Make it fresh.”

Marble windowsills are like hardwood floors. You can paint them, but you’ll regret losing the original beauty and durability. Restore, don’t paint.

Marble is porous. When Marco tried again with a primer, any humidity from cooking or watering plants got trapped under the paint. Bubbles formed, and the paint cracked.

Marco, eager to please, grabbed a can of leftover trim paint. “Of course you can paint marble,” he said. “It’s just stone.”