1.   Gravure a rotary printing process where the image is etched into the metal plate attached to a cylinder.

2.   For some people, it takes all their strength to hold still while an image is being etched onto the skin.

3.   The shorter the wavelength of the light used to etch the image, the sharper the image becomes.

4.   In aquatint, the metal plate is dusted with rosin powder, which is heated and creates a sandpapery surface where the image can then be etched.