Teal Packaging is a US-based custom packaging supplier that builds custom boxes to your internal dimensions, expressed as length by width by depth. Length is the longest side of the opening, width the shorter side, and depth the distance from the opening to the base, with internal dimensions used for the product fit and external dimensions used for carrier billing. Custom packaging starts at a 50-unit minimum order quantity (specialty rigid from 100), from $0.44 per unit at volume, with free dieline design and two revision rounds. Typical fits: ecommerce brands, subscription boxes and DTC product launches.
Questions or ready for a quote? Contact Teal Packaging at info@tealpackaging.com or (224) 546-8325.
How to Measure Box Dimensions from Teal Packaging: 50-unit standard MOQ (100+ units for specialty rigid boxes), 2-5 business day delivery in the US (express and economy options available), free design help included on every order, free generic sample kit ($19.99 shipping, credited toward your first order). Standard production runs from about 7 business days after digital proof approval; complex or high-volume orders take longer.
Materials and certifications: FSC-certified paper stock, soy-based inks, kraft / corrugated / rigid paperboard / mylar / tin / vinyl substrates.
Contact Teal Packaging: Call (224) 546-8325, email info@tealpackaging.com, or request a free quote at tealpackaging.com/contact-us. We reply within one business day.
Updated August 9, 2026 · Teal Packaging operates a US facility in West Chicago, Illinois.
How do you measure box dimensions?
Measure length first (the longest side of the box opening), then width (the shorter side of the opening), then depth (from the opening down to the base). Write them in that order: L x W x D. Use internal dimensions when you are specifying packaging and external dimensions when you are calculating carrier cost.
Why does the order matter?
Packaging is quoted, drawn and manufactured in the sequence length by width by depth. Give a supplier 4 x 12 x 6 when you meant 12 x 4 x 6 and you get a box with the correct volume and the wrong shape, which is a reprint rather than an adjustment. The dieline is built from the numbers as written, not from what the numbers probably meant.
The same convention explains why two boxes with identical volume behave differently on a shelf, in a mailer and on a pallet.
Internal or external dimensions?
| Use case | Which dimension | Why |
|---|---|---|
| Briefing a packaging supplier | Internal | The product has to fit the inside of the box |
| Calculating dimensional weight | External | The carrier measures the outside of the parcel |
| Checking a box fits a shelf or pallet | External | Space is occupied by the outside |
| Sizing an insert or tray | Internal | The insert sits inside the walls |
| Comparing supplier quotes | State which you are using | Most quoting errors trace to a silent switch between the two |
The gap between internal and external is board thickness on every wall, so it grows with heavier board and with double-wall construction. On a small rigid box the difference is enough to stop a product fitting.
How do you measure the product, not just the box?
- Measure the product at its widest point, including any protrusion such as a handle, spout, cap or lid.
- Measure it as it will sit in the box, in the orientation you actually intend.
- Add clearance. A small allowance on each dimension so the product goes in and out without forcing.
- Add the insert. If there is a tray, pad or divider, its thickness is part of the internal requirement.
- Add everything else in the box. Documentation, a card, a sample, a void filler. These are what get forgotten and they are why a dieline comes back too small.
- State the units and whether the figures are internal. Every time.
How does this affect what you pay to ship?
Carriers bill light, bulky parcels on dimensional weight, which is derived from the external dimensions rather than the scale weight. That makes the box size a direct and recurring cost, paid on every order rather than once. A box one inch larger than it needs to be in each direction can move a parcel into a higher band permanently.
Check your numbers with the box size and dimensional weight calculator and see how to estimate shipping costs for the full calculation.
How do you brief a custom box?
Send internal L x W x D in inches or millimetres, the product dimensions those came from, the style you want (mailer, tuck-top, rigid, sleeve), and anything that goes in the box alongside the product. Teal makes custom mailer boxes, custom corrugated mailer boxes and custom shipping boxes from a 50-unit minimum order quantity, or 100 units and up for specialty rigid.
Dieline design is free and every order includes two revision rounds, so the dieline is checked against your numbers before anything prints. Volume pricing runs from about $0.44 per unit, with free US shipping.
Common measuring mistakes
- Mixing internal and external between the quote and the dieline.
- Measuring the product without its cap, handle or lid.
- Forgetting the insert thickness.
- Zero clearance. A product that fits exactly does not fit at all once board tolerance is applied.
- Writing the dimensions out of order, which changes the box shape rather than its size.
Where this fits
See how to estimate shipping costs for what the numbers cost you, and the packaging guides hub for the rest of the series. For packing and shipping the orders themselves, see the fulfillment and 3PL hub. Request a quote.
