3D VS 4D NUMBER PLATES

Last reviewed October 2026  ·  Ali Plates UK

How each one is actually made

This is the part most comparisons skip, and it explains every other difference between them.

A 3D gel plate starts as an ordinary printed plate. The registration is printed flat onto the reflective face, then a clear polyurethane resin is applied over each character and cured. The resin forms a domed bubble that follows the shape of the letter underneath. What you are looking at is a printed character seen through a lens of clear gel.

A 4D plate is built the other way round. Each character is cut from a sheet of solid black acrylic, usually 3mm thick, on a laser cutter. The finished letters are then bonded onto the plate face. The character is a physical object sitting on the plate rather than an image underneath a dome.

That one difference, printed-then-coated against cut-then-stuck, drives how they look, how they wear and what they cost.

Side by side

Are both legal?

Yes, provided the plate is made to the British Standard. Raised characters are not a loophole or a grey area. GOV.UK lists them as a permitted option in the same breath as a border or a national flag.

What decides legality is the same checklist for every plate on a UK road, raised or flat. The plate must:

• Be made from reflective material
• Show black characters on white at the front and black on yellow at the rear
• Use characters in a single shade of black
• Carry no background pattern
• Be marked BS AU 145e
• Show who supplied it

Characters also have to be properly fixed. A letter that can be picked off is a problem whichever method made it, and a plate missing a character is an MOT failure and a police matter.

The 3D plate that actually was banned

There is a real ban behind the confusion, and it is worth understanding because it is not the one people think.

Before September 2021 you could buy a 3D effect plate. Nothing was raised on it at all. The characters were printed flat, using grey shading down one side of each letter to fake the look of depth. It was a drawing of a 3D letter, not a 3D letter.

From 1 September 2021, plates fitted from that date must show characters in a single shade of black. A printed character using black and grey to suggest a shadow is, by definition, more than one shade. So that style became non-compliant overnight.

Coverage at the time reported it as "3D and 4D plates banned". It was neither. Genuine 3D gel and 4D plates were unaffected, because a raised character casts a real shadow instead of a printed one, and the character itself remains a single solid black.

Which should you choose?

There is no better one, only a different look.

4D suits sharper, more modern cars, and anyone who wants the lettering to read as deliberate and engineered. The solid acrylic character also takes a knock better than a resin dome, and at 3mm it throws a harder shadow that stands out more in daylight.

3D gel suits anyone who prefers a softer, glossier finish, or wants raised lettering at a lower price. The dome catches light in a way flat acrylic does not, which some people much prefer.

One practical note: the numbers are marketing terms, not standards. 5D usually means a laser cut acrylic character with a gel dome on top, combining both methods, but there is no rule saying so. What one seller calls 4D another might call 5D. Read the construction, not the number.