Coatings and radar-absorbent material, or RAM, make only a small contribution to the efforts to hide an airplane from enemy radar, but without them, no airplane can be truly stealthy. The F-22 first gets a base coat of radar-absorbent or deflective materials, over which is applied a topcoat developed by Boeing to counter a broad range of wavelengths, including infrared. The formula was tailored for the Raptor’s wing edges to deter wideband radars; a ceramic RAM cools its hot exhaust nozzles.

When RAM is illuminated by radar, its molecules oscillate, converting the radio waves or microwaves into heat, which dissipates from the skin, rather than reflecting the energy back to its source. The paint’s properties act in roughly the same way as your kitchen’s microwave oven.