Energy from a radiation can be either absorbed or reflected by an object. Thus, if the object is a good absorber of radiation then it is a poor reflector and vice versa. That means objects that are good reflectors of radiation are poor absorbers. Note also that when we heat up objects, they emit the energy that they have gained as radiation. This means that a good absorber of radiation is also a good emitter and a poor absorber of radiation is a poor emitter.