For almost 50 years, each letter that leaves the Summer Isles on the boat to the mainland has carried two stamps.
While one will feature the Queen’s head and insure its journey on the mainland, the other will have been produced by the Summer Isles Philatelic Bureau, one of the smallest stamp issuers in the world, to take it over the water to Achiltibuie.
Set up in 1970, the private postal service on Tanera Mor, the largest of the Summer Isles where just two people live at present, was set up by former island owner Kenneth Frampton after Royal Mail stopped collecting mail due to lack of demand.
Now Mr Frampton’s enterprise, born out of a practical need, has flourished into a unique quirk of Summer Isles life.
Stamps and first day covers produced by the bureau are popular both with collectors and tourists, who can often be seen quickly scribbling postcards by the pier at Ard-na-Goigne as the MV Patricia gets ready to leave for mainland with its small mail bag.
Lizzie Williams, whose family are selling Tanera after almost 20 years on the island, said she hoped the stamp tradition would continue with the new owners.
READ MORE: Tanera Mor island for sale for £1.95m
The latest issue of stamps was produced last year to celebrate the new album release of local musician Mairearad Green.
As a result, Ms Williams was handling a “flurry of orders” addressed to simply The Summer Isles Post Office, Isle of Tanera Mor, Scotland.
Each stamp, which illustrate and aspect of the island’s nature or culture, costs just 30p.
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Ms Williams said: “It would be great to see this continue as the post office is an integral part of Tanera. It is 46 years since the first stamp was produced and it does gives the island this unique element. There are no many islands that have their own post office.”
Ms Williams said she knew little about stamps before she arrived on Tanera around three years ago but has enjoyed this aspect of life on Tenera.
She said; “It is a nice thing, none of us were stamp collectors but preparing the issues every year meant that it made you focus on a different element of life here.”
The first definitive issue produced by Mr Frampton, with the approval of the Royal Mail, featured local fish species superimposed on a map of the islands.
When Ms Wiliams parents, conservationists Bill and Jean Wilder, bought Tanera in 1996, the Post Office had been dormant for 10 years but the couple quickly produced a series of designs featuring the original 1855-1861 Ordnance Survey map of the Summer Isles.
Ms Williams said the 1996 issue also saw the change from pound and pence to the Gaelic ‘Punnd Sassanach’ (PS) and ‘sgillinn’ (sg) “in an echo of the wider national effort to revive the language.”
A donker - or special frank - is also produced with each new issue and may typically feature a crab, or a mountain, or a bird or a fish with the stamps printed in Dundee.
The designs are produced “organically”, sometimes following an offer from someone who has visited Tanera.
Turner-prize nominated artist Calum Innes, originally from Edinburgh, visited the island and produced the first abstract design for the Summer Isles stamps.
Ms Williams said her favourite issue was the 1980 issue Birds of the North West designed by the renowned ornithologist and printmaker Robert Gillmor.
She added: “There are also hills; crofters; boats of every type; tartans; clans; scouts and salmon. Even Royal Jubilees and unsuccessful Royal Weddings. Designed by a range of artists and photographers, they make an intriguing and eclectic collection.”
She added that getting to grips with the finer details of philately, with miniature sheets, control sheets and Se-tenants sheets to organise, as well as filler cards which give full details about the stamps, had been a “steep learning curve.”
Ms Williams said: “The design of each of these is very ‘of its time’, and handling the early items feels like having a little bit of history in my hands.”
As well as standard First Day issues, the bureau sometimes produces ‘inter-island’ issues which must travel from Tanera to one of the other Summer Isles to receive a special frank.
Ms Williams said these were of “particular interest to the philatelically-inclined” but also involved a minor adventure, usually by a kayak.
After arriving at the shore, the challenge was to frank the stamps while keeping them dry, clean - and midge free, she said.
Tanera Mor is currently for sale in three lots at a total price of £1.95m. The post office, three houses and a cafe are included in lot 1, which has been valued at £700,000.