One of the most coveted in-flight experiences is opening the amenity kit to discover its delights - a miniature flacon of perfume or a cult- brand lip balm, perhaps, nestled with the toothbrush and eye mask.

Full-service airlines increasingly compete to deliver a superior experience and win the loyalty of fliers in premium cabins, using designer kits, fancy sleepwear and pillows as objects of desire.

In May, Qantas released its Qantas Curates initiative, working with Australian contemporary art curators to select artworks from 16 Australian artists, designers and photographers to create unique amenity kits which represent Australian culture.

Ms Olivia Wirth, Qantas Group executive of brand, marketing and corporate affairs, says the airline's vision is to grow awareness of contemporary Australian art and give travellers a collectible piece to take home.

"Along with in-flight pyjamas, we know amenity kits are an important part of the international business class experience.

"Customers love the functionality of our kits and many use them after their flight as make-up bags, an evening clutch or to carry their mobile phones. So, the exposure is broad," she says.

Other airlines, such as Emirates, Qatar Airways and Singapore Airlines, which target the luxury travel market, partner like-minded luxury lifestyle and fashion labels such as Bulgari, Salvatore Ferragamo and Bric's luxury luggage maker to create their in-flight amenity kits.

Mr Adrian Eugene Seet, 44, founder and editor of lifestyle website Superadrianme.com, says travellers have come to expect amenity kits on board, particularly in premium cabins, just like they expect hotels to provide toiletries.

Sleepwear, a comfortable pillow and blanket or duvet for a good sleep on long-haul or red-eye flights are also important for a pleasurable in-flight experience, he says, adding: "Amenity kits sometimes give me the chance to try new brands and products.

"Some kits have also educated me about a country's culture and practices and they make great gifts for family and friends."

Event organiser and frequent flier Desmond Tan, 40, appreciates the comfort that an amenity kit's practical items - such as a toothbrush, lip balm and moisturiser - provide during a flight. But he says the kit's real value is in a well- thought-out bag.

"Most regular travellers are always looking for a great bag for charging cables, gadgets and adaptors and I have used some amenity kit bags for years," he says.

"It's an opportunity for the airline to continue to remind the passenger of its brand long after he has left the plane."

The Sunday Times rounds up some of the best in-flight amenity kits that airlines offer.

Qantas

In May, Qantas launched a series of business class amenity kits with a twist.

In a project called Qantas Curates, artwork by 16 of Australia's up-and- coming artists, photographers, designers and influencers will appear on 16 amenity kits - eight for men and eight for women.

Each pouch features artwork - from photography and fine art to indigenous art and textile design - that is replicated on an accompanying wraparound eye mask.

Also included are toothpaste, toothbrush, earplugs and travel socks as well as a line of hydrating hand cream, lip balm and face moisturiser created for Qantas by award- winning Australian spa Aurora.

Qantas has released two kits so far: Bubblegum Dystopia, a photographic pop-art collage by Hobart- based visual artist Jacob Leary, for women; and No Queen Blues/ Unwind, an abstract geometric print of blues, white and grey, which is the hallmark of Melbourne artist Liam Snootle, for men.

A new pair of kits will be released every quarter.

Business class passengers on overnight flights will also get a soft grey cotton Qantas pyjama set.

In the airline's first class service, which is offered only on the A380s and Boeing 747s from Australia to London (via Dubai) and to Dallas, Los Angeles and New York, the pyjama and amenity kits have been designed by Australia-born, Paris- based fashion designer Martin Grant, who is also Qantas' creative director of fashion.

The 100 per cent cotton unisex pyjamas in navy with black trim are presented in a Martin Grant drawstring bag with a matching pair of travel slippers.

The accompanying amenity kit includes a wraparound eye mask; travel socks; toothbrush and toothpaste; and exclusive hydrating products by Aspar, such as hand cream made with sweet orange, rosehip oil, shea butter; and an ultra-hydrating face moisturiser made with aloe, sweet orange and rose geranium.

Emirates

With a reputation for taking its planes, service and amenities to the next level of luxury, Emirates partnered luxury Italian brand Bulgari to develop its latest round of stylish amenity kits and even introduced "moisturising" loungewear.

Each premier class has eight kit designs - four for men and four for women. The business class kits are made in grey fabric for men and silver fabric for women, while the kits for first class are made of charcoal grey leather for men and pale grey leather for women.

Revamped every nine months - the most recent edition was released in December last year - the kits highlight Bulgari's Eau Parfumee au The Noir, a woody-floral scent for men and women inspired by Chinese black tea.

For men, each kit contains a foldable brush, tissue paper, dental care kit, deodorant, shaving foam, Bulgari The Noir body lotion, aftershave and miniature spray and a Truefitt & Hill razor in business class, with an additional lip balm and oshibori refreshing towel in first class.

The women's kits include a mirror, Bulgari The Noir body lotion, nourishing face emulsion and spray, and oshibori refreshing towel in business class, plus an additional hand cream and lip balm in first class.

For long-haul overnight flights, Emirates also recently released a new pyjamas set for its first class passengers.

According to an Emirates spokesman, these pyjamas are the first moisturising loungewear specifically designed for an airline.

They use Hydra Active Microcapsule Technology: billions of capsules of naturally moisturising, nutrient- rich sea kelp essence have been applied to the fabric and these are gently released during movement, keeping skin soft, refreshed and hydrated during the flight.

The sleep suits include matching slippers and eye mask that come in a stylish felt pouch.

On board, passengers also have free use of luxury spa products from award-winning Irish brand Voya. Its shampoo, conditioner, body wash, cleanser, body moisturiser, hand wash, soap and hand cream, which have been created exclusively for Emirates, are available in the A380's signature shower spa.

Singapore Airlines

Singapore Airlines may not provide an amenity kit in business class, but eyeshades, slippers and socks are distributed on board, while the fully reclining seats are lined with soft bedding by James Park Associates design firm.

Perfume, moisturiser and facial mist by London perfumer Miller Harris are stocked in the bathrooms.

On select long-haul and overnight flights, travellers in first class get a stylish sleeper suit and an amenity kit by Italian luxury goods company Salvatore Ferragamo.

The burgundy kits for women includes a cleansing towel, hand cream and a 30ml bottle of Ferragamo's Signorina perfume. The men's navy cloth kit includes an aftershave balm and a 30ml bottle of Ferragamo's Acqua Essenziale Blu cologne.

Qatar Airways

Routinely ranked one of the best airlines in the world, Qatar Airways launched its first and business class amenity kits, which look like miniature suitcases and travel bags, in an exclusive three-year partnership with Bric's high-end Italian luggage designer in December last year.

The kits feature products from Castello Monte Vibiano Vecchio, an environment-friendly olive oil company from the Umbria region of Italy. The nature-focused items include a lip balm, hydrating facial mist and anti-ageing moisturiser for business class passengers, with an additional night recovery cream for first class kits.

The sleek leather kits come in burgundy and cream for women and black for men, and include matching eye masks, earplugs and socks.

Passengers in the Middle Eastern airline's first and business classes on overnight flights also receive 100 per cent cotton sleep suits and slippers from British premium homeware label The White Company.

Air France

The Air France amenity kits are the picture of understated chic.

Available in blue, grey, orange and turquoise, the latest unisex business class kits were launched in February and new styles and colours are introduced every six months.

Inside, customers will find an eye mask, earplugs, comb, shoe horn, toothbrush, toothpaste and mouthwash, and a lip balm and moisturiser by French cosmetics company Clarins.

Passengers can also request shaving kits and refreshing towels during the flight.

In the La Premiere First Class cabin, the amenity kit takes the form of a sleek faux leather case embossed with the Air France logo. It carries products by the exclusive French cosmetics and skincare brand Carita and includes a moisturising face cream, eye cream, lip balm, hydrating hand cream, pen and comb.

Air France also introduced a new La Premiere sleep suit last month. The unisex black cotton pyjamas are folded within an elegant faux-felt and leather pouch, which passengers can take with them, along with a matching comfort kit of slippers, socks, shoe horn and a shoe bag.

Cathay Pacific

Hong Kong's flagship carrier places a premium on natural products for its business and first class amenity kits, which are stocked with skincare goodies from renowned Australia brands Jurlique and Aesop.

In business class, the minimalist kit was designed by Seventy Eight Percent, a Hong Kong-based design company that specialises in innovative, high-quality bags for professionals. Inside, passengers will find, among others, a lip balm, balancing day care cream and citrus hand cream, all by Jurlique, as well as anti-skid socks and a monitor-cleaning cloth.

The kits for first class passengers were designed by Aesop in grey for men and camel for women. The men's zip-top case includes Aesop camellia nut facial hydrating cream, rosehip seed lip cream as well as mouthwash, hairbrush and monitor-cleaning cloth.

Women's kits include an additional Aesop rind concentrate hand and body balm. On flights to and from Hong Kong, the cases have been designed so the inbound and outbound kits can be clipped together for multi-purpose use.

British Airways

First and Club World business class amenity kits are available on all British Airways flights from Singapore to the airline's network of 185 destinations around the world.

Business class customers get an exclusive selection of products from Elemis Skincare, an award- winning anti-ageing British brand which has been stocking the airline's kits since 2013.

Rather than a typical pouch, the kit is designed as a dark or light-blue drawstring bag - decorated with a print of the London skyline - which can be used as a shoe or laundry bag after the flight.

In addition to socks, toothbrush, toothpaste and pen, the women's kits include Elemis pro-radiance hand and nail cream; pro-collagen marine cream for deep hydration; and ultra-conditioning beeswax lip balm.

The men's kit also includes a razor and soothing shaving gel formulated with skin-soothing arnica and jojoba oils.

The airline's new first class kits, launched on Singapore-route flights in May, were created by luxury British brand Liberty London.

They feature prints from the label's textiles archive and products by natural body and skincare line Aromatherapy Associates.

The women's bag also functions as a stylish wristlet and is made in the Oriental-inspired Christelle floral print. It includes firming eye serum; triple rose moisturiser; deodorant; and basics such as cotton wool and toothbrush.

The men's bag is made of a black embossed and textured material with a Liberty London's Felix Raison paisley print lining. Inside, travellers will find a moisturiser; cooling eye gel; razor and shaving gel; lip balm, deodorant, brush and comb, toothbrush, toothpaste and a pen.