The width is defined by the length of the first free-standing line
in the puffer's plume. The formula for this is 12n+1-s, where n is
the number of middle segments, and s is the number of cells covered
by the little 3-cell, 5-unit puff-suppressors on the upper edge of
this otherwise symmetrical pattern.
Here, n=4, and s=6+5+5. The Y-shaped puff-suppressors can have 5,
6, or 7 units of spacing on between them, or between one of them and
the end. You only need 2 or 3 such suppressors to produce any
puffer width.
Notice that placing random debris behind the puffer sometimes
affects the plume permanently - even turning it asymmetrical if the
debris was asymmetrical. It also affects the period of the puffer,
that is, the number of generations it takes to repeat. By
increasing the width, the period can be made to rise exponentially,
surpassing 10^6 at a width of only about 70. But the most amazing
thing is that it has a half-life on the order of 10^8 generations.
