David mentioned that the white cart for his laser printer does not produce a very opaque white.
To be fair, my ALPS has the same problem (I haven’t seen David’s decals so I can’t compare actual opacity.
While the printer should print a white base coat then a white overlay, mine won’t (the head scratches the first print while laying down the second one).
So I print two decals and simply apply one, set it with Micro Sol, let it dry thoroughly, then apply the second decal over the first.
For reporting marks and road numbers it works fine.
I use Tango Papa paper which is thin so I don’t have a problem with the overall thickness of the two decals.