Aromatic postage stamps infused with eucalyptus oil will give mail deliveries a distinct Australian scent when they are released this month.
The printer of the Australian stamps said the scent could freshen up the musty files of stamp collectors for decades.
"The eucalyptus scent is encapsulated into little bubbles and we put that into a printable varnish," Graeme Lidgerwood, the sales manager of the print firm Ego, said. "It could last forever. The scent will only wear off when you rub the surface to break the micro bubbles."
The Farming Australia issue, on sale from May 17, features four 60c stamps depicting native horticultural products: bush honey, macadamia nuts, tea-tree oil and eucalyptus oil.
However only one will feature the scent of a eucalypt forest embedded in what Ego calls the Scentprint varnish, a technique which has been used to liven up magazine covers.
Mr Lidgerwood said the original scent for the print process came from the US. However, at Australia Post's insistence, the varnish was topped up with eucalyptus oil from the local maker Bosisto.
The scented stamp is available only in a special sheet that retails for slightly above face value, at $6.45 for 10 stamps. Individual stamps bought over the counter, or on self-adhesive rolls and booklets, will not carry the eucalypt scent.
Meanwhile, the opera singer Dame Nellie Melba, the first Australian woman to feature on a postage stamp 50 years ago, is the subject of another commemorative issue next week that marks 150 years since her birth.
Australia Post will issue a 60c stamp on Tuesday, which adapts an image from the Melba portrait by the Australian artist Rupert Bunny, who painted the singer between her engagements on the opera stages of Europe in 1901 and 1902.