Another advantage to K4 decals is that the same set is usually offered in multiple scales.  I have made use of this in obtaining heralds in smaller sizes that I've need for specific projects.  Case in point:

For these HO scale DT&I flatcars, I needed a very small version of the compass herald complete with the "Connections" slogan.  K4 makes a set for DT&I gondolas with coil steel hoods in them.  This set has two different sizes of this herald (one size for the side of the gon, the other for the coil hoods).  I ordered the N scale version of this set and got the small heralds that you can see on these models.

Craig Wilson