Hi – I have come across a few houses with particleboard panels on the inside walls and ceiling. Having worked in the particlebaord industry for 20+ years this is how it works: All production facilities have at times problems producing 2nds, these 2nds may show a small imperfection one one side only. Those boards can be purchased by employees at a discount (at least it used to be in the good old days) and lining a house on those conditions worked out cheaper than gyprock. Plus you dont need to cover joining strips, there is no painting, easier to clean, the only drawback is repairs are not quite as easy if you damage a panel, while an 8’x4′ can be easily taken off and replaced, matching the colour would be near to impossible after a couple of years exposure to the light.
Hope that helps understand some of the background?
If I can help further let me know…re technical differences etc.
cheers
Hardy