I know of a "ventail" in the costume sense, but there is a specific perfumery application/object?.    From Wordnik.com.  [Play it like a harmonica...] Reference

Obs. a1330 Roland & V. 863 His ventail he gan vn-lace & smot of his heued in e place.    From Wordnik.com.  [Medallion Vulcan | SciFi, Fantasy & Horror Collectibles] Reference

The helmet had a ventail, a mouth flap that could be pulled across and fastened with a strap.    From Wordnik.com.  [The Pillars of the Earth]

Other senses of the OF. word (and of the related forms ventele, ventail, and vental) are fan, vane (of a windmill), sluice, shutter, leaf (of a folding door or picture).    From Wordnik.com.  [Medallion Vulcan | SciFi, Fantasy & Horror Collectibles] Reference

She puts on his hauberk with its strong meshes, and laces on his ventail.    From Wordnik.com.  [Four Arthurian Romances] Reference

Then he alighteth over him and taketh off the coif of his habergeon and unlaceth his ventail.    From Wordnik.com.  [The High History of the Holy Graal] Reference

Then he alighteth over him, lowereth his coif, unlaceth the ventail, and smiteth off his head.    From Wordnik.com.  [The High History of the Holy Graal] Reference

The other drags him by the helmet, tearing all the fastening, and he strikes from his head the ventail and the gleaming coif.    From Wordnik.com.  [Four Arthurian Romances] Reference

He alighteth over him, unlaceth his ventail and smiteth down his coif, then striketh off his head and presenteth it to Perceval.    From Wordnik.com.  [The High History of the Holy Graal] Reference

Erec grabs him by the helmet and forcibly drags it from his head, and unlaces the ventail, so that his head and face are completely exposed.    From Wordnik.com.  [Four Arthurian Romances] Reference

The tears ran down from his comely eyes right amidst his face and through the ventail, and, had he durst make other dole, yet greater would it have been.    From Wordnik.com.  [The High History of the Holy Graal] Reference

Her marriage is deferred to bk.v. 6, when she tilted with sir Artegal, who "shares away the ventail of her helmet with his sword," and was about to strike again when he became so amazed at her beauty that he thought she must be a goddess.    From Wordnik.com.  [Character Sketches of Romance, Fiction and the Drama, Vol. 1 A Revised American Edition of the Reader's Handbook] Reference

The helmet, and the "coiffe" beneath it, protected the head; the "ventail" of linked meshes was worn across the lower part of the face, and was attached on each side of the neck to the "coiffe", so that it protected the throat; the greaves covered the legs.    From Wordnik.com.  [Four Arthurian Romances] Reference

King Arthur rode thitherward and alighteth before this little house, and entereth thereinto and draweth his horse after him, that had much pains to enter in at the door, and laid his spear down on the ground and leant his shield against the wall, and hath ungirded his sword and unlaced his ventail.    From Wordnik.com.  [The High History of the Holy Graal] Reference

F. ventail masc.    From Wordnik.com.  [Medallion Vulcan | SciFi, Fantasy & Horror Collectibles] Reference

Then he fastened his ventail.    From Wordnik.com.  [The Pillars of the Earth]

He lowereth his ventail and taketh off his helm.    From Wordnik.com.  [The High History of the Holy Graal] Reference

Harness, pair of armours, 2 bascinets, poleyns, vambraces, rerebraces, pisane, ventail, and gauntlets.    From Wordnik.com.  [roland Diary Entry] Reference