I came across a small problem when producing mug wraps with drop shadows in Photoshop. My printer driver (Ricoh SG3110DN) doesn't have a Flip Image setting so I have to do this in Photoshop.
The problem.
My design had elements with Drop Shadow Effects, with the shadows falling to the bottom-right. However, when I reversed (horizontally flipped) the image for printing, the shadows didn't flip. It appears that Photoshop will only flip the image layer and not the effects attached to it.
The solution.
The best solution I found was to right-click all the layers with Drop Shadow Effects and convert them into Smart Objects. Flipping the Smart Objects also flipped the shadows.
Here's a quick view of the technique ...
BEFORE FLIPPING
Both boxes are on Normal layers, with the same Drop Shadow applied.
AFTER FLIPPING
The top box has been converted to a Smart Object before flipping and the shadow flips with it, unlike the bottom box which is still a Normal layer.
Basic stuff, I know, but not everyone is comfortable with Photoshop so I hope this is of use to anyone struggling with the same problem.