Although absorption rates vary from one type of radiation to the next, dark exteriors—especially black, matte surfaces—are particularly good absorbents of infrared radiation. Infrared radiation is heat radiation that travels by way of electromagnetic waves.
On the other end of the spectrum is nuclear radiation, which emits three different kinds of radiation. Alpha radiation is the weakest and is easily absorbed by skin or even a piece of paper. Beta radiation is stronger, but it can be absorbed by a few centimeters of human tissue or aluminum. Gamma radiation is the most dangerously powerful, and needs an object with a high atomic number, such as lead, to absorb it.