How do I measure my product for a magnetic closure rigid box?

What do Length, Width, and Height mean on a magnetic closure rigid box?

Following FEFCO and Paperboard Packaging Council rigid setup box conventions, every dimension you enter on our magnetic closure rigid boxes quote form refers to the usable inside cavity of the four-wall base tray, read with the box sitting on a table and the front magnetic flap facing you

1. Length (L, left to right): The horizontal span across the front tray wall where the hinged magnetic flap drops down and snaps shut. Because the back spine hinges along the Length axis, a wider Length gives you a panoramic horizontal unboxing.
2. Width (W, front to back): The horizontal depth from the inside face of the front magnet wall back to the inside face of the rear spine wall.
3. Height (H, bottom to top): The usable vertical depth from the inside floor of the base tray up to the underside of the closed lid.

How much space should I add for an EVA foam, EPE foam, or card insert?

Whether you are packing a single glass perfume flacon in custom perfume boxes or a three-piece executive kit in custom corporate gift boxes, your interior insert needs enough border width around each cutout so the foam walls never tear or collapse during shipping. Use these clearance rules when calculating your inside tray Length, Width, and Height

1. Outer foam border to tray wall (add 0.4 to 0.5 in / 10 to 12 mm per side): Keep at least 1/2 inch of solid EVA or EPE foam between any product cavity and the four rigid tray walls. That means a single bottle measuring 3.0 × 2.0 inches needs an inside tray of at least 4.0 × 3.0 inches.
2. Bridge between multiple items (add 0.4 to 0.5 in / 10 to 12 mm between cavities): When placing two or three items side by side, leave at least 1/2 inch of foam webbing between each cutout so glass bottles or jars cannot clink together.
3. Bottom foam pad + head clearance (add 0.25 in base pad + 0.125 in top air gap): If your product is fragile (such as a glass spirits bottle or ceramic mug), place a 0.25 inch foam floor pad underneath the cavity and leave 0.125 inches (3 mm) of vertical air space above the highest point of the product so the magnetic lid closes flush.
4. Finger notches for easy lift-out: Our structural team adds two semi-circular 0.6 inch (15 mm) finger notches on opposite sides of the foam well so the recipient can lift a snug bottle or watch box pillow out cleanly.

What are standard magnetic closure rigid box sizes by product type?

Every magnetic box order at CubitPack is built to your exact custom size starting from 50 boxes, with zero die or plate charges. Use the reference table below as a starting point for common luxury, beauty, and gifting products

How do box dimensions affect board thickness and magnet count?

As your inside Length, Width, and Height grow, both the chipboard caliper and the front-flap magnet configuration scale up so the walls never bow and the lid snaps shut with uniform tension from corner to corner. You can also compare how board thickness behaves across styles in our guide on magnetic closure vs book-style and collapsible rigid boxes.

1. 1.5 mm (60 pt / ~1000 gsm) chipboard: Best for compact boxes under 4.5 inches in Length (such as small jewelry cases and gift card holders) where a slimmer wall profile looks refined.
2. 2.0 mm (80 pt / ~1200 gsm) chipboard: The industry standard for 80% of perfume, watch, cosmetic, and medium gift boxes between 5 and 10 inches in Length.
3. 2.5 mm to 3.0 mm (100–120 pt / 1500–1800 gsm) chipboard: Recommended whenever Length exceeds 10 inches or total packed product weight exceeds 2.5 lbs (such as custom spirits boxes or multi-item PR vaults).
4. Two vs four concealed neodymium magnets: Two magnets spaced across the front flap hold lids up to 10 inches wide. On boxes 10 inches or wider in Length, we embed four magnets (two pairs near the left and right corners) so the wide flap never lifts at the ends.

How do I calculate outside dimensions for an outer corrugated mailer?

If you plan to mail your finished magnetic closure rigid box directly to customers through UPS, FedEx, or USPS, protect the soft-touch or foil-stamped exterior inside a fitted corrugated outer box or bubble-lined shipper. To estimate the outside dimensions of a closed 2.0 mm magnetic closure rigid box from its inside tray size, add 0.30 inches (7.5 mm) to the inside Length, 0.35 inches (9 mm) to the inside Width (which includes the back spine and overlapping front magnet flap), and 0.25 inches (6.5 mm) to the inside Height. For example, an 8.0 × 6.0 × 3.0 inch inside magnetic box measures roughly 8.30 × 6.35 × 3.25 inches on the outside, so an 8.75 × 6.75 × 3.75 inch corrugated shipper gives you room for kraft paper or bubble wrap. When you request a quote on CubitPack (from 50 boxes, with 10–14 business day standard turnaround or 4–5 business day rush), our team sends your exact inside and outside structural drawing plus a free digital proof and 3D mockup before payment. Read our companion guide on magnetic closure rigid box dielines and paper wraps to see how artwork wraps around those dimensions.

What are the most common measurement mistakes on magnetic closure boxes?

Avoid these five sizing errors before finalizing your rigid box and foam insert dimensions

1. Giving outside ruler measurements instead of inside tray dimensions. Two layers of 2 mm chipboard and the outer case reduce the inside cavity by 0.25–0.35 inches.
2. Leaving less than 0.4 inches (10 mm) of EVA foam border between the product cutout and the rigid tray walls, which causes thin foam edges to tear or bow.
3. Setting inside tray Height exactly equal to the product height with zero head clearance. If the bottle cap touches the underside of the lid, the front magnets will pop open.
4. Swapping Length and Width so a wide horizontal PR kit hinges along its short side like a narrow notepad instead of opening panoramically across the long side.
5. Using only two center magnets on a wide 12-inch+ box, allowing the outer corners of the front flap to sit slightly raised.

Packaging for this

Custom Magnetic Closure Boxes

Custom Perfume Boxes

Custom Jewelry Boxes

Custom Watch Boxes

Custom Corporate Gift Boxes

Custom Spirits Boxes

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