Color-enhanced Scanning Electron Micrograph (SEM) showing pink foam lumps (diameter between 2 and 5 cm) used as heat insulation for attics. The smooth surface of the lumps was opened with a blade to show the interior, consisting of air cells about 250 micrometers (quarter a millimeter) in diameter. Image width: 2736 micrometers. Magnification: 36.5x if the image is printed 10 cm wide. Bar: 500 micrometers.