On this page 9 sections
Magnetic car signs hold on and leave your paintwork alone when three things are true: the panel is steel, the spot is flat, and both the door and the back of the sign are clean when it goes on. Add one habit, taking the sign off once a week, and most of the problems people run into simply never happen. The rest of this page is the detail: how to test your car, where to put the sign, how to fit it and what to do with it when it’s off.
Test the door before you spend a penny #
A magnet grips steel and nothing else. Lots of cars now use aluminium, plastic or composite for some body panels, and even a steel door can have a plastic trim strip running across it. So the first job costs nothing: take a fridge magnet out to the car and try it on the exact spot where the sign will go, on both sides.
If the fridge magnet slides off or won’t grip, a printed sign won’t either. If you’re still unsure, send the make, model and year through our contact form and we’ll help you work it out before you order anything.
Finding a flat patch #
The sign needs to lie flat across its whole area. Wherever it bridges a dip, air gets underneath, and air under the edge is what lifts a magnet off at speed. Stay away from:
- Creases and swage lines pressed into the door.
- Handles, badges, trims, rubbing strips and the base of the wing mirror.
- Shut lines. A sign must never span the gap between two panels, like front door to back door.
- Windows, lights and number plates. Don’t cover any of them. GOV.UK sets out the rules on displaying number plates.
Measure, then pick a size
Run a tape across the flattest part of the door and note the height and width. Then choose a size that leaves a few centimetres spare on every side. Our car door magnetic signs are printed on 900 micron magnetic sheet in these sizes:
| Size | Millimetres |
|---|---|
| A3 | 297 × 420 mm |
| A2 | 420 × 594 mm |
| Landscape | 450 × 300 mm or 600 × 300 mm |
| Larger | 610 × 457 mm |
| Custom | From 100 mm up to 1000 × 600 mm |
There are also dedicated pages for A3 magnetic signs and A2 magnetic signs. Got a van? Magnetic van signs go up to 1000 × 600 mm.
What to have ready #
- A bucket of warm water with a splash of car shampoo.
- A soft microfibre cloth, plus a dry towel or cloth.
- A tape measure, and a strip of masking tape if you like to mark positions.
That’s the whole kit. No tools, no adhesive, nothing that touches the paint except the magnet itself.
Fitting magnetic car signs in six steps #
Allow about ten minutes the first time. After that it’s a two-minute job.
- Clean the door. Wash the panel with the shampoo, rinse it and dry it fully. Any grit left behind gets trapped under the sign, scratches the paint and stops the magnet lying flat.
- Clean the sign’s back. Give the dark magnetic side a wipe with a damp cloth, then dry it. Grime stuck to the magnet does just as much damage as grime on the door.
- Mark your height. Measure down from something fixed, like the lower edge of the window glass, so the left and right signs sit level with each other. A bit of masking tape makes a handy marker.
- Put the top edge on first. Hold the sign by two corners, touch the top edge to the door and lower the rest down like a blind. Don’t shuffle it sideways into position: that scrapes any grit across the paintwork.
- Press out the air. Sweep a flat palm outwards from the centre until the sign is touching everywhere. Pay extra attention to the front edge, the one facing the way you drive.
- Do the fingernail test. Pick at each corner with a nail. Any corner that lifts without effort, or perches on a bend in the panel, means the sign needs a flatter home before you drive off.
The weekly lift-off #
Once a week, take the sign off. Damp and fine dust creep in underneath, and if they sit there for a month you can end up with marked paint, or a sign-shaped patch that doesn’t quite match the rest of the car. Clean both surfaces, let them dry, and put the sign back using the steps above.
A few more habits that keep magnetic car signs flat and grippy:
- Car wash? Sign off. Brushes and high-pressure jets can peel it away, and it may get damaged or lost in the machine.
- Very hot or very cold weather with the car parked for days: take it off. Heat softens the sheet, and a frozen sign is hard to lift without bending.
- Freshly painted panel? Don’t fit it yet. Ask the bodyshop how long the new paint needs.
- Peel from a corner. Never bend the sign in the middle to get it off. A creased magnet won’t sit flat again.
Motorways, wind and the front edge #
A clean sign that’s fully in contact holds well at normal speeds. Trouble starts when the front edge lifts: air gets under it and can peel the whole sign away, which is dangerous for whoever is behind you. So check your magnetic car signs each time you set off, and again before a long motorway run. If a sign has been brushed by a hedge, knocked in a car park or has a curled corner, take it off and refit it properly.
Taxis and private hire #
Licensed taxi and private hire drivers should speak to their council’s licensing team before fitting anything. Many councils have rules about what can appear on licensed vehicles. Our taxi magnetic signs are printed from your artwork, so you can match exactly what your licence allows.
Where to keep them when they’re off #
Store the sign flat, printed side up, somewhere dry and at room temperature. The best spot is flat against something steel, like a fridge or the side of a filing cabinet, where it stays dead straight. Things to avoid:
- Rolling it tightly or folding it.
- Leaving it on the parcel shelf in the sun.
- Stacking two signs face to face.
- Keeping it next to bank cards.
If you want graphics that stay on for good, a magnet is the wrong tool. Self-adhesive vinyl is the permanent option, and our guide to applying vinyl stickers walks through it. If magnets suit the way you work, the whole vehicle magnets range is worth a look.
Ordering and dispatch #
Car door magnets dispatch in 5 working days on standard, 4 on express and 6 on saver, counted from when your order and artwork are confirmed. They’re made to order and dispatched from the UK. Delivery to the UK mainland is £7.95, or free on orders of £100 or more after discounts (artwork fees don’t count towards that). Full details are on our delivery page.
Look after magnetic car signs with a clean panel, a weekly lift-off and flat storage, and they’ll keep doing their job every time the car moves.