I haven't found a good combination I like. If if the molding of the plastic is on the inside (backs of gashapon medals), it looks decent. But, if it is flat on the inside (front side), it looks just horrible.
I tried with chrome spray paint. The backs of gashapons look alright, but on the front, it just looks gray, and looses a lot of detail. Even adding a coat of glossy black didn't help with the chrome. It doesn't look right.
I tried to different applications of the chrome (a normal spray, and a second slower application taking a couple of hours). It doesn't look like chrome at all. It looks very shiny on the inside, but, it is not reflecting the light properly through the plastic. Then I tried adding a coat of glossy black.
Just letting you know what I tried.
Also, it looks like the molding on the inside of the Premium medals are a little different. Less plastic bridges or pieces sticking out, which become very apparent on the normal medals when you paint them as there are dark spots.
Edit: Warning The following images may be disturbing. A valuable possession, personal and to the OOO fans, has been harmed in the making of this collage:[hide]
[/hide]