Taken by the Hubble Space Telescope in April 002, this image shows the upper 2.5 light-years of the nebula, a height that equals 23 million round trips to the moon.

x-heights. If you make a light weight and the black weight of one typeface you'll have to make sure that the black weight has a bigger x-height than the light weight (top line drawing).

If the type is printed in big sizes there can be a much smaller difference between the x-height of the light and the black weight (bottom line drawing).