How do I measure the thickness of an aluminum foil sheet?

To measure the thickness of an aluminum foil sheet, you can use a digital caliper or a micrometer. Place the foil between the jaws of the caliper and take the measurement. If you don't have these tools, you can use the 'multiple fold' method: fold the foil in half repeatedly and measure the total thickness after several folds, then divide by the number of layers to estimate the single layer thickness. For a more precise measurement, especially for thinner foils, consider using a thickness gauge designed for measuring thin materials.