Renaissance Wax is a brand of wax that is highly esteemed among clayers for creating a nice finish. Apologies in advance to fans, but I want to be clear about what this wax does and what it does not.
The marketing for Ren Wax speaks of its use in the British Museum to protect artifacts. This gives the impression that it also creates a protective finish on polymer clay. This is a misunderstanding. Museums must preserve delicate materials, such as wood, ivory, polished stone, leather, and bone, that can dry out or oxidize. Historically, beeswax was used for this. Beeswax is a lovely material, but it builds up and becomes sticky, tends to yellow, and will collect dust and grime. So Ren Wax came along and was marketed to fill this niche. It works well for its intended purpose. It can also be used to coat and protect paintings (Dorland’s Wax from @jacquardproducts is similar).
However, polymer clay does not dry out or oxidize in the air. It does not need to be protected in this manner. And Ren Wax (or beeswax for that matter) is just a thin coating. It cannot protect against abrasion or physical damage from wear.
But what can Ren Wax do? It works for clayers in the same way that lotion works to remove the dull or white cast you see on your skin in the winter. Ren Wax, rubbed into a piece of dark polymer clay, will add a slight shine, remove dustiness, and minimize the appearance of scratches from sanding. It really works well to make dark polymer pieces “pop”. It can also be used to change the appearance of surface treatments, making THEM deeper or darker in color.
But just like lotion, it wears off. You’ll need to reapply from time to time. It is not a permanent finish.
It’s also not necessary. Ren Wax is pretty expensive and also has a strong odor that some people dislike. You’ll find that lotion, petroleum jelly, lip balm or even paste wax will do the same thing, often with a nicer smell and certainly with a lower cost.
One last thing. If your polymer piece has scratches from sanding, then address that. Those scratches can be removed with a finer grit of sandpaper, and gentle buffing will bring up a lovely shine. (And yes, I have a course for that!)