The world’s smallest Christmas card

The UK’s National Physical Laboratory (NPL) have created the world’s smallest Christmas card, with each page just 15 micrometres wide and 20 micrometres tall.

One micrometre is one-millionth of a metre, so you could fit 200 million of these tiny cards on to the surface of one standard postage stamp!

To create the card, scientists carved the design and message into a miniscule sheet of platinum-coated silicon nitride using a focussed ion beam – a jet of charged particles.

The card itself, and the message inside, are only visible under a very powerful microscope. To transform it into a normal ten-centimetre-tall card, you would have to magnify it 5,000 times!

The tools and techniques employed to create the card are mainly used to develop cutting-edge methods for analysing materials at the micron-scale. It is hoped that this research will help us continue to miniaturise electronics and create new battery materials.

Dr David Cox, Research Fellow at NPL, who created the card with his colleague Dr Ken Mingard, said: “While the card is a fun way to mark the festive season, it also showcases the progress being made in materials research on this scale. We are using the tools that created the card to accurately measure the thickness of extremely small features in materials, helping to unlock new battery and semiconductor technologies. It’s a genuinely exciting development that could help to make new technologies and techniques a reality.”

Find out how this extraordinary feat was achieved in the video below:


This is the world’s smallest Christmas card, created by NPL out of Platinum-coated silicon nitride. Measuring in at 15×20 microns, you could fit over 200 million cards in a single postage stamp. It is too small to be seen by the naked eye and it would take a powerful microscope for you to read the festive message inside. The tools used to make the card are usually used to accurately measure the size of features of new battery or semiconductor materials. Copyright: NPL


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