My way of protecting against the dryness indoors, - with a saran wrap. Figs enjoy the sun behind the south facing window in December.
This is especially good to have for long and tall cuttings, they have a harder time proving the moisture to the ends.

Enjoy!

Looks like a good way to promote mold growth. By the way, most loss of water is through the stoma on the underside of the leaves.

No mold at my place, 40% relative humidity. You may be right about the leaves as a moisture loss but until the leaves appear, the cutting is drying up.

Greenfig,

Mold is everywhere.......you breathe the spores in daily.  

Greenfig - you may have low enough humidity that you won't have problems with mold using your approach.  However, to echo comments above the figs would lose moisture from the leaves and not the stems.  I'm not sure there would be any benefit for plastic wrap prior to leaf appearance but I think once the cutting leafs out (as yours has) the plastic wrap no longer serves a purpose.  But anyway it looks like you are having good luck with SIPs so good work there.

they look very good, so perhaps the roots are well on their way also...  the plastic is not too tight.. be careful not to get too hot on them.