You should be able to find some at Napa or whatever chain autoparts. Duplicolor, Plasticote, VHT and others make it, in colors even. VHT is one of the better paints I have used. It is also rumored that the Harley Davidson brand sold though dealers is THE wrinkle paint to use, I have never tried it... part# 98606CJ
One heavy coat works best, just enough so it dosn't run...

Though it will wrinkle in it's own good time while drying at room temperature, heating and preferably baking above 200 degrees F gives more consistant results... bar-b-q grills and even hair dryers will work in a pinch. I suggest you experiment on something else first.