If creation on another thread is allowed, is it safe to access a PGraphics in a different thread than the one it was created in?

The general question is: does PGraphics use any thread-local resources that would make it unusable in a thread other than the one it was created in?

Edit: Synchronization is done external to the PGraphics, I'm not concerned about general thread-safety of it, just making sure there are no thread-specific resources allocated (e.g. in wgl a context must be used only in the thread it is active in).

Thanks,

J