Level 3 Finish
Specified for areas that do not require any decoration (ie. above ceilings or inside service shafts etc). These areas are not painted or decorated and the final appearance is not important.
Level 4 Finish
The standard level of finish for plasterboard lining where normal decoration by painting is to be carried out. Unless otherwise specified, a level 4 finish shall be taken as the default standard level of finish for plasterboard (as defined in AS/NZS 2589 (2007).
Level 5 Finish/Skimming
The highest level of finish (when specified) for plasterboard lining where the desired outcome is to have a finished surface that is as free as possible from surface defects and visual blemishes.