I’m thinking of making a silicone mold of one of my figures, so that I can make some duplicates. The figure has already been painted, and I’d just like to know whether the molding process will screw up the paint job on the original figure.

Anyone (maybe Richard K.) know about this?

If you spray the figure first with a silicone spray or mold release, I doubt if the paint would be harmed.

It depends on the complexity of the figure and the surface you are painting over.
I’ve made molds of painted sculpty figures without spraying the with mold release agent and nothing at all happens to the paint.
On the other hand, I’ve made molds of wooden figures without spraying mold release agent and some of the paint chips off.
I think if your figure is made out of a non porous surface like bakable clay then you are save doing a straight pour. With the exception that you give at least 48 hours for the paint to set and that the clay was clean of any releasing agents prior to painting.

Here is a link to some information on silicone products. I personally have never tried so can’t comment like others. Having said all of that the research says that some types of silicone (as on this link) do a fine job of fitting until cured, then releasing once set properly. I have plans for the same methods in the future simply because I am troubled by not being able to find some specific characters from the time period I am after.

http://www.bare-metal.com/polytek-mold-materials.html

There are also some good articles on modifying figures on these boards, so over time, a mold could be made to recreate several at one time in a single mold. Let us know how it works out if you go this route.