The world of fashion has always been renowned for its one-upmanship — but now things have taken a new turn.

It’s no longer enough to stay at some of the world’s most expensive hotels — for the ultimate brag you need the merchandise, too. High-end hotels have teamed up with leading design houses to launch their own collections that go way beyond boring bathrobes and slippers.

But don’t worry if your budget doesn’t stretch to a five-star stay, all the goods are available online.

Whether you’re looking for luxurious loungewear, a striking print scarf, nightwear that says romantic weekend, or eco-swimwear — with crucial branding — check out the fancy hotel merchandise you can buy without checking in.

CAP OFF A STAY AT THE RITZ

Ritz Collection and Frame

Dinah Van Tulleken reveals fancy hotel merchandise you can buy without checking in. Pictured: Frame x Ritz Paris blanket, £821

The Ritz Paris hotel has teamed up with LA label Frame for a 22-piece collection, including a sweater (pictured), varsity jacket and baseball cap with the hotel's name and crest The casual pieces are available from net-a-porter

The Ritz Paris hotel has teamed up with LA label Frame for a 22-piece collection, including a sweater (pictured left), varsity jacket and baseball cap (pictured right) with the hotel’s name and crest

The Ritz Paris hotel has chosen LA label Frame for its first foray into fashion collaborations. The 22-piece collection, available on net-a-porter, includes American classics — a crew-neck sweater, varsity jacket and baseball cap with the hotel’s name and crest.

The casual pieces are lent Parisian chic by the branding, though pricing isn’t so sweet, starting at £70 for the Ritz Water Bottle. A pair of off-white cashmere socks costs a mere £87 (frame-store.com). But compared to rooms at the Ritz Paris, which start at £926 per night, these are a steal.

PAJAMAS FIT FOR ROYALS

Claridge’s and Derek Rose

London hotel Claridge¿s asked luxury nightwear designer Derek Rose to produce a bespoke collection for adults and children (pictured)

London hotel Claridge’s asked luxury nightwear designer Derek Rose to produce a bespoke collection for adults and children (pictured)

Fashion insiders love Claridge’s legendary London hotel, which boasts royal connections so deep it is known as an annexe to Buckingham Palace.

Luxury nightwear designer Derek Rose, who has designed for, was asked to produce his bespoke collection for adults and children. All PJs have matching eye masks, robes and hand-embroidered slippers, all in pure cotton.

Available in Claridge’s signature jade green, pale pink, light blue or white (claridges.co.uk), the range starts at £65 for the eye mask. It’s pricey, but when the cheapest Claridge’s room, starts at £660, it’s not so bad.

SWANKY SWIMWEAR

Nobu Hotel Ibiza Bay and Love Brand & Co

London-based ethical swimwear label Love Brand & Co have teamed with the super cool Nobu Hotel Ibiza Bay for a capsule collection (pictured)

London-based ethical swimwear label Love Brand & Co have teamed with the super cool Nobu Hotel Ibiza Bay for a capsule collection (pictured)

London-based ethical swimwear label Love Brand & Co have teamed up with the super cool Nobu Hotel Ibiza Bay where a stay can cost up to £5,473 per night.

Their capsule clothing collection supports IbizaPreservation, which protects threatened seagrass meadows in the seas around Ibiza and Formentera.

Featuring a Posidonia seagrass design it includes swimming trunks made of recycled polyester, £90, and a linen shirt, £105. See lovebrand.com.

SUPER STYLISH SLIPPERS

Mandarin Oriental and Aquazzura

Mandarin Oriental Hotels has worked with Italian footwear brand Aquazzura to create limited-edition slippers (pictured)

Mandarin Oriental Hotels has worked with Italian footwear brand Aquazzura to create limited-edition slippers (pictured)

A favorite of the rich and famous, Mandarin Oriental Hotels (rooms at the Hyde Park branch in London starting at £750) has worked with Italian footwear brand Aquazzura to create limited-edition slippers — black and white for men, and aqua green and white for women, with tassel details. There’s also a yellow and white design for children with pom-poms. From £265, shopmo.com.

WRAP UP INTO LUXURY

The Luxury Collection and Margherita Missoni

Marriott Hotels has collaborated with Margherita Missoni for a limited-edition scarf (pictured)

Marriott Hotels has collaborated with Margherita Missoni for a limited-edition scarf (pictured)

For guilt-free shopping look no further than Marriott Hotels’ collaboration with Margherita Missoni. The Italian designer, and heiress to the Missoni fashion house, has created a stylish scarf inspired by her travels around India.

The Luxury Collection Limited-Edition Scarf, £200, is available at luxurycollection store.com. All proceeds will be donated to sustainable living eco-charity, the Collective Good Foundation.