Fridge magnets: strength, construction and the spec nobody asks about
Flexible rubber vs rigid magnets, what holding force actually depends on, and why 'what will it hold?' is the one question that prevents the most common magnet disappointment.
OFFPRESS editorial · Based on direct observation of real pieces · Stage: Preparing artwork · 2 Sept 2026
Most custom magnets are ordered by artwork and size. The property that decides whether customers love or quietly resent them — holding force — is the one nobody specifies, because you can’t see it in a product photo. This page is the spec conversation, before you order.
The two constructions
Flexible rubber magnets — ferrite (iron-oxide) magnet powder compounded into a rubbery sheet — are what most printed merch magnets are. Thin, light, cheap, printable in any die-cut outline, and they hold by being multi-pole magnetized across their face. They are also, physics being physics, the weaker option per square centimetre.
Rigid magnets — thicker, harder magnetic material — hold much harder for their size. They cost more, weigh more, and come in fewer format freedoms. You choose rigid when the magnet has a job (holding notes, photos, a kid’s artwork through a fridge door) and flexible when the magnet is the product (a collectible that should stay put on a fridge and not scratch it).
What holding force actually depends on
Three factors, all knowable before you order:
- Contact area. Force scales with the magnet’s footprint — a magnet twice the diameter holds far more than twice as much. This is why big-format magnets feel “strong” and small stamp-shaped ones feel delicate.
- Thickness — up to a point. More magnetic material helps until the circuit saturates; beyond that, extra thickness adds cost, not force.
- Air gaps. Every layer between magnet and steel — a coating, paper, dust — cuts holding force sharply. A fraction-of-a-millimetre gap costs a double-digit share of the force. Practical consequence: a magnet that grips a bare fridge may slide on a painted or textured one.
What this means in practice: “magnet strength” isn’t one number a supplier either has or lacks. It’s a match between what the magnet must hold and the construction you spec — which is why the useful sentence to send any supplier (us included) is:
“It needs to hold two sheets of paper on a painted steel door.”
That sentence — not “strong magnets please” — is what lets the supplier choose the right backing and prove it in a sample.
What we check on real pieces
The board scenes in our magnet gallery are doing this test visibly: the pieces hang under their own weight on steel, holding their own footprint. The honest checks we’d encourage any buyer to run on samples:
- Slide test: how easily does it slide down a vertical surface with paper under it?
- Gap test: same on a painted or textured surface, not just bare steel.
- Edge test: does the die-cut edge stay flat, or curl away and lose contact?
Packaging, briefly
Magnets ship with one quirk: they attract each other. Individually bagged (standard OPP) prevents face-scratching in transit; stacked loose, domed or thick magnets can mark each other. If your magnets ship in one box to a convention, ask for individually bagged — it’s standard for us, but it’s worth confirming with any supplier because it’s invisible until unboxing day.
Tell us what your magnet has to hold when you request a quote — that single line changes the construction we propose, and it’s the difference between a collectible and a tool.
Researched and written by the OFFPRESS editorial desk. General production principles are kept separate from OFFPRESS specifications — anything that depends on our supply chain is marked as confirmed with your quote, not stated as a blanket promise.
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Fridge Magnets
The same artwork, a different object on the shelf. Printed, domed and backed to hold what you need it to hold.
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