With Dezeen's Brexit passport design competition underway, we're taking a look at existing travel documents that any citizen would be proud to slap down at customs.

From a flipbook-style animation to a secret music score that appears under blacklight, these five passports show designers experimenting with what can be a limiting format.

Should these designs ignite your own creative spark, head to Dezeen's Brexit passport competition entry page. We are calling for entries that present a positive vision of the post-Brexit UK to the world, and that represent all its citizens.

Norwegian passport

Oslo-based Neue Design Studio won the competition to redesign Norway's passports in 2014, although the finished product is yet to enter circulation.

The passport is distinguished by its minimal double-page illustrations of landscapes from different parts of the country, which transform under UV light to include the Northern Lights in the sky. The covers for the three variations (standard, immigrant and diplomatic) feature highlighter hues with a small coat of arms in the lefthand corner.

Read more about the Norwegian passport by Neue Design Studio ›

Finnish passport

The Finnish passport is probably the only one to double as entertainment for travellers caught in long customs queues. It features an illustration of an elk that appears to walk when you flick the pages like a flipbook.

Designed in 2012 by a consortium working with the Finnish Police Board, it has unfortunately been replaced from the start of 2017 by a new design from Gemalto that introduces a flying swan in place of the elk.

Swiss passport

According to writer Richard Hollis, Switzerland was the first country to have its passport professionally designed. The current design, which has been around since 2003, has a bright red cover debossed with a pattern of Swiss crosses.

Inside, where most countries opt for pastels and muted tones, Switzerland has featured primary colours overlaid with patterns that continue to play on the cross shape.

Hungarian passport

A number of countries make use of hidden illustrations that only show up under blacklight as one of their security features. Norway has the Northern Lights, Canada has a collage of national symbols, and China makes the Great Wall look like its springing off the page.

But one of the best uses of the technique comes from Hungary, which has embedded a message in its passport. Under UV light, the passport displays the score to the Szózat, one of the country's national anthems.

Japanese passport

In 2016 the Japanese foreign ministry revealed the design for its new passport, set to enter circulation in 2019. The design removes the border from the already elegant red or blue front cover, which features the Imperial Seal of Japan in the centre and, above it, the words "Japan passport" in seal script, an ancient form of writing.

Inside, the new passport will be filled with masterpieces – specifically, ukiyo-e woodblock artist Katsushika Hokusai's famous landscape series, Thirty-six Views of Mount Fuji.

Dezeen's Brexit passport design competition is free to enter and has a top prize of £1,000. Closing date is 24 March 2017. More details at www.dezeen.com/passport