Knockdown finish

Knockdown is basically joint compound thinned and sprayed in a consistent pattern then troweled flat. Knockdown must be sealed and painted because it only covers 75% of the drywall; the paint fills in the background. Knockdown also hides imperfections and can be sprayed on walls as well as ceilings.  For a proper job knockdown must be sprayed out of a machine (spray rig) not out of a hand held hopper.
Hopper spray inconsistently leaves you with an unprofessional job.