For many applications, a narrow absorption band may be desirable.
Nature(Dec 11, 2012)
The spectrum of chlorophyll, the green colouring matter of plants, shows two very strong absorption bands in the red.
Various, Encyclopaedia Britannica, 11th Edit...(2012)
A photograph by Prof. Slipher of Neptune’s spectrum “shows the spectrum of this planet to contain many strong absorption bands.
Gore, J. Ellard, Astronomical Curiosities—Facts and...(2012)