I have started putting decals (from Little Big Men)on my Gaul shields.
The instructions for these are precise and tell you what you need to know. The trouble is believing the instructions.
You have to cut out the boss area and trim to the edges of the shield decal before application. I thought this was going to be a real pain but these decals only require you get close -- not precise. -- so . . . actually the trim process isn't all that bad.
Then you stick the decal front (well it looks like the front) directly onto the shield. The sticky isn't too bad either as you can move the decal around quite a bit or peel it off and start over -- so positioning is not an issue.
After considerable angst and trepidation I applied water, waited a minute and peeled off my first paper backing . . . Will-ahh!! it worked -- like wow did it work. The 'front' is really the back, the decal colors are fantastic, and the decal position is perfect!
The only error I made was applying the decal to a non-white under surface. You know, this wasn't all bad because I have a lot more than 48 Gaul shields to do (they only make 48 different shield designs for A&A figs). Using different under coat colors effectively gives you a lot more options.
These are great products -- highly recommended!
mjc