Renaissance Wax for most applications. For other uses, such as inside spherical shells where access is difficult, I melt solid microcrystalline wax, pour that in, swill it around & pour it back out. This works best if the object is warmed up. I have also used this to some extent on small fragile organic objects whereby I dunk the item into a pot of the melted wax, leave it in for long enough to heat the object (not long, up to 10 seconds or so) and then remove it & let the excess wax drain off back into the pot; if the object is very warm then the wax will largely drain off it & leave behind only a very thin coating, which is what is wanted, but if the object is cool then the wax will want to solidify on contact & will deposit a thick coating which will not look great and may turn white.
