Plastidip. Only thing is it turned kinda yellowish, like a dirty uneven cream color. Was hoping for a nice bright even white color. But oh well. May try one of the other colors it comes in next time.
Probably has something to do with the out gassing of the chemicals in the tires..As the tires dry out they release some of the stuff that makes them pliable. An extreme case would be your typical gumwall left in a hot place for a long time...the tire gets covered with "stuff" that looks like it melted in the sun.
Are you guys wiping the tire down with any solvent before painting? Enamel reducer works great to make a tire black again...
Back in the day you used to be able to buy whitewall tire paint from JC Whitney, etc, or port a walls ...and lots of used car dealers actually hired guys to come around and redo the whitewalls on their stock so all four tires would match. They could put a nice 3/8 whitewall on a black tire no problemo. Durability??Who knows.
Took a look at your abum to see the tires closer up... You forgot to share this one!! Cool shot!