Decals should be easy. But I find I'm fighting with them daily and some of our products have 50 or more per assembly. 

When first mating a decal the side with the image shows until you start to mate, then it disappears. So if you don't recall which side is the mating surface you may accidentally mate it upside down.

Compounding the problem, when mated, the image surface doesn't actually show until you place another decal. Then the latest one disappears. 

As you continue to place more decals some seemingly at random show and others don't. A shoddy workaround seems to be to toggle the perspective view setting. That tends to work until the next decal is placed.

Any advice appreciated!