What Shane said.
In addition, FYI, A higher number such as 85lpi, actually means the dots will be smaller. It's easy to get confused when first trying to understand the dot count and think that larger numbers represents (larger dots). It's just the opposite.
(We are fitting and counting rows of dots) in a square inch or a fixed space. So 85lpi means there are 85 rows of dots in a line. Fewer lines, means the results are providing LARGER dots to fill that same space.