Burning single layer image to BD-RE DL?

[dbminter]

What happens when you burn an image that fits on a single layer BD-RE to a BD-RE DL?  Is only Layer 0 written to?  Is any padding written to Layer 1?  If so, is the remaining space on Layer 0 and all of Layer 1 written with padding? 

[LIGHTNING UK!]

All BD disc are treated like single layer discs (just with different capacities). Once a layer is totally full, the drive moves onto the next one.