As with any miniature (metal or plastic), it is advisable to wipe them with soapy water to remove any residue of the release agent that may interfere with the good adhesion of the first varnish. As the miniature bones are made of flexible plastic, they can take bad poses in the blister pack: you can easily correct or change these by immersing the miniature in very hot water, then immersing it in ice water to fix the new laying.