transformer oil

Its probebly appropriate to mention that anyone wishing to do this would be ill- advised to recover the oil from old transformers or other components. The PCB content might make the stuff deadly rather than inert.

I'm not quite sure which properties of transformer oil lead you to characterise it as "inert"?

One of its most troublesome characteristics, in its normal use, is that it is hygroscopic. That is, it absorbs moisture from the atmosphere. That is why transformers have to be sealed, and the air space, to allow for expansion, connected to atmosphere via a silica gel breather.

Chris

What I asked was some inert transparent oil to preserve some ornament in a jar for decoration, someone from a blog mentioned transformer oil. Anyway thanks for the cautionary advice.

PL