If a recent report from Korea is to be believed, the LG G4 will be the only 2015 flagship to still use plastic in its construction, after Samsung switched to metal for the S6.
The report, picked up by ZDNet Korea (translated) claims that LG is looking into new CNC (Computer Precision Control) production methods so it can produce its own metal bodies. It's alleged that LG won't be able to make the switch to a metal chassis in time for the LG G4 launch, but it goes on to say the LG G4 Note could.
While a plastic build would theoretically place it below its peers, it would still provide some benefits. Most notably of which would be a removeable battery and microSD card slot. It's also possible that LG could take the self-healing technology from the G Flex 2 and feature it on the G4.
There's also a very slim chance that LG could halt production of the G4 until its new metal processing method is up to full speed. But this is a very very slim chance.
As ever, until there's official confirmation from LG, we'd suggest taking these rumours with a pinch of salt for now. We'll bring you the latest news as and when we hear it.