I agree with dj about Future. Wonderful stuff. I usually use Microscale or Aeromaster solutions, depending on the decal. These don't work as well on all decals, though. The strongest, for softening the decal, seems to be Solvaset. It can "melt" some decals, and sometimes needs to be thinned with distilled water. A good selection & experimentation can lead to pleasing results. Hope this helps.