LED Crystal Fingerprint Keychain Square

A square block of optical crystal with a fingerprint engraved inside it, on a metal cap and ring holding an LED. The square gives a single print the most even setting of the three keychain shapes: the impression sits centred with equal space on all four sides, and the piece reads the same whichever way up it hangs from a bag or a set of keys. Press the cap and light enters the crystal from above, so the ridges come through as clear white lines rather than a grey blur.

One Print, Given Room

A fingerprint is not a picture and it does not benefit from being crowded. Centred in a square, the pattern is the only thing in the block and the eye goes straight to the ridges. A rectangle gives a thumb impression more room across than down, and a heart says openly what the object is about; this shape does neither and simply frames the print evenly, which is why people who want the object to look like an object rather than a memorial tend to choose it.

Why the Light Is Built In

Ridges lying a fraction of a millimetre apart separate only when light passes through the crystal behind them. Daylight does that by itself, which is why the necklace versions need no light; a keychain spends its life in pockets and cars, so it carries its own. The LED sits in the metal fitting at the top and meets the engraving from behind, and the whole block glows with the print standing inside it. Switched off, it is simply a clear crystal that reads well in daylight.

Sizes and Sending the Print

Three sizes are made, all cut to the same depth. A larger block will not add detail the original impression never had, so choose by how it will hang rather than by how much of the print you hope to see.

The proof costs nothing and arrives before engraving. A 3D Preview before you order is $9.99, refunded in the price. Where Standard cuts 3 million points, Ultra HD cuts 4.5 million. That is up to 50% more detail. A light base underneath is what makes it read.

Engraved wording is included at no cost. Repeat copies are half price. Send a sharp, well lit photograph taken from the waist up. A designer looks at every file by hand.