Quick answer: Line a rigid plastic box with a ferrous/steel sheet, put neodymium magnets flush under each base, and leave headroom for banners. Magnet-to-steel avoids polarity mistakes; skip flimsy fridge magnet sheet for heavy models.
What you need
A rigid plastic box that does not flex (Really Useful Boxes and similar work well). Flexing breaks magnet contact.
Ferrous/steel sheet or rubber-steel sheet cut to the tray floor — not soft decorative magnet sheet alone.
Neodymium disc magnets sized to your bases. For plastic infantry on ~32 mm bases, many hobbyists use about 3×2 mm to 5×2 mm; measure the hollow under the base first. See our magnet size chart (editorial guide).
Cyanoacrylate or epoxy; optional green stuff to seat magnets flush.
Build steps
Clean the box floor. Cut the steel sheet to fit and glue it down with a strong adhesive so it cannot lift.
Seat one magnet flush in each base underside. Press against baking paper while curing so nothing sits proud.
Test: tip the tray gently. Add a second magnet on heavy resin or tall models.
Leave clearance under the lid for spears and wings — magnets stop sliding, not crushing.
When foam is still better
Flights with rough handling, very spiky models, or one-off trips often favour foam in a hard case. See the transport hub.
Display at home after magnetising
Open tiered stands still work — models sit by gravity. Browse the modular display stand collection or the stands compared guide.
Frequently asked questions
Do I need N52 magnets?
Usually no. A flush N35–N42 disc with enough diameter beats a tiny N52 that tears out of the glue.
Can I use magnetic sheet under the models instead?
You can put steel bottoms on bases and magnet sheet in the box, but steel sheet + magnets in bases is the stronger common DIY.
Will this scratch paint?
Magnets go under the base, not on paint. Foam is what rubs varnish in transit.
Is DIY cheaper than a ready-made magnetic case?
Usually yes for materials; you pay in time. Ready-made trays win if you travel weekly.
Where should I store the box at home?
Cool, dry room — not loft or garage. See the storage hub.
Use a rigid outer box; soft bags alone can flex and peel models off a sheet. After a DIY build, shake-test over a soft towel before the first event.