Custom Mailer Boxes

Mailer Boxes: specifications

Mailer Boxes: price breaks

How the estimated unit price of a 9×6×3" mailer box in E-flute corrugated, white changes with quantity. Setup costs are spread over more boxes as the run gets longer, so the per-box price drops sharply in the first few tiers.

Popular sizes for mailer boxes

Sizes are inside dimensions (length × width × height) in inches. Any custom size is available at no extra cost; these are simply the sizes brands order most.

Material options and how they affect price

Estimated unit price at 1,000 units for a 9×6×3" mailer box with full-color printing, by material. Material choice changes look, strength and recyclability as well as cost.

Printing options compared

How the print specification changes the estimated unit price of a 9×6×3" mailer box in E-flute corrugated, white. One- and two-color printing carries a small plate charge that matters less as quantities grow; full-color digital and offset printing have no plate charge in our model.

What is a custom mailer box?

A mailer box is a one-piece, die-cut corrugated box that folds into a rigid tray with an attached hinged lid. The lid has a tuck flap that slides into the front wall, and the side walls are double thickness, folding over themselves and locking into slots in the base. Because the structure locks itself, a mailer box closes without tape and opens cleanly, which is exactly why it became the default box for direct-to-consumer brands, subscription programs and gift kits.

In the packaging industry this structure is usually called a roll end tuck front (RETF) box, and it corresponds closely to FEFCO style 0427 in the European corrugated code. You will also hear it called a literature mailer, e-commerce mailer, subscription box or simply a tuck top mailer. They all describe the same idea: a strong shipping box that doubles as a presentation box.

Mailer boxes sit in a sweet spot between plain brown shipping cartons and expensive rigid gift boxes. They are strong enough to go through UPS, FedEx and USPS parcel networks on their own, yet they print beautifully on the outside and the inside, so the moment a customer lifts the lid becomes part of your brand.

Why brands choose mailer boxes

• No tape, no clutter. The self-locking design means a cleaner unboxing and faster packing on your line.
• Two print surfaces. The outside sells the brand on the doorstep; the inside delivers the surprise when the lid opens.
• Parcel-ready strength. E-flute and B-flute corrugated board survives typical parcel handling for products up to roughly 10–15 lb when sized correctly.
• Reusable and giftable. Customers keep good mailers for storage and gifting, which keeps your brand in their home.
• Ships flat. Mailers arrive flat-packed, so a thousand boxes take up a fraction of the space of assembled cartons.

Anatomy of a mailer box

Understanding the parts helps you brief your designer and read a dieline correctly. A standard roll end tuck front mailer has eight main panels:

When you open the free Dieline Generator and choose Mailer box, you will see each of these panels labeled on the flat layout. The double side walls are the reason a mailer's flat blank is much larger than the finished box: a 9 × 6 × 3 in mailer needs a blank of roughly 22 × 22 inches before it is folded.

Materials and board grades

Almost all mailer boxes are made from corrugated board, a fluted paper medium glued between two flat liners. Two things matter: the flute size (thickness) and the liner (the printable surface).

Flute options

• E-flute (about 1/16 in thick). The standard for mailers. It is thin enough to fold crisply and print sharply, but has enough cushioning and stacking strength for most DTC products under 10 lb. If you are unsure, start here.
• B-flute (about 1/8 in thick). Roughly twice as thick as E-flute. Choose it for heavier products (candles in glass, ceramics, books, multi-item kits), larger boxes over about 14 in long, or anything that will be stacked in a warehouse for weeks.
• F-flute / micro-flute (about 1/32 in). Very thin and smooth. It is used for small premium mailers and retail cartons where print detail matters more than crush strength.

Liner options

• White (bleached) liner. The brightest surface for full-color printing. Colors look clean and photography reproduces accurately. Most branded mailers use a white outside liner.
• Kraft (brown) liner. Unbleached, naturally brown, and slightly cheaper. It signals natural or eco-minded brands and looks excellent with one or two dark ink colors. Bright colors look muted on kraft because the brown shows through.
• White outside, kraft inside. A common compromise: a bright printed exterior with a natural interior.

Board strength for mailers is normally specified as 32 ECT (edge crush test) for single-wall board. That rating is plenty for parcel shipping of typical consumer products. Read our corrugated cardboard guide for how ECT, Mullen burst and caliper relate to each other.

Tip: Board thickness changes the inside dimensions. If you switch from E-flute to B-flute after your dieline is made, the box needs to be resized, otherwise your insert or product may no longer fit.

Printing options for mailer boxes

Mailer boxes can be printed with three main methods. The right one depends on quantity, design complexity and budget.

Inside printing

Printing the inside of a mailer is what turns a box into an experience. A bold interior color, a pattern, a thank-you message on the inside lid or simple usage instructions all cost far less than outside finishes like foil, yet they create the "wow" moment customers film and share. Most brands print full color outside and one or two colors inside, or a single flood color inside to keep costs down. See interior printing for ideas.

Color accuracy

If your brand color matters, give us a Pantone (PMS) reference. Digital and CMYK presses simulate Pantone colors very closely on white board; offset printing can run a true spot color. On kraft board colors shift darker and warmer, so ask for a printed sample if color is critical. Our printing guide explains CMYK, Pantone and rich black in detail.

Finishes and add-ons

Mailers are mostly corrugated, so not every luxury finish suits them. These work well:

• Matte or gloss aqueous coating. A clear water-based coat that protects print from scuffs in transit. Usually included.
• Matte or gloss lamination. A thin film that adds rub resistance and a premium feel, common on litho-laminated mailers.
• Soft-touch lamination. Velvety and premium on high-end mailers. It can show scuffs in rough shipping, so we suggest it for boxes that go inside an outer shipper.
• Spot UV. A glossy highlight on your logo against a matte background. Works best on laminated board.
• Foil stamping. Gold, silver or holographic foil for logos. It needs a smooth laminated surface on corrugated.
• Custom inserts. Die-cut paperboard or corrugated inserts that hold products in place. Essential for glass, multi-item kits and anything that should not rattle. See custom inserts.
• Tear strip or zipper. A perforated strip that makes opening easy and tamper-evident, useful for subscriptions.
• Branded tissue, stickers and cards. Low-cost accessories that complete the unboxing. Browse packaging accessories.

How to size a mailer box correctly

Box size drives cost, product safety and shipping fees. Mailer boxes are always quoted by inside dimensions: Length × Width × Height, where length and width are measured across the opening and height is the depth of the base.

1. Measure your product (or packed kit) at its largest points. Include any inner packaging: a jar plus its carton, or several products plus tissue.
2. Add clearance. Add about 1/8 in to each dimension for a snug fit, 1/4 to 1/2 in if you use tissue or crinkle paper, and 1 to 2 in all around if you need cushioning for fragile items.
3. Check the height. Mailers look best when they are shallow relative to their footprint. Very tall mailers (height greater than width) are harder to fold and less stable; consider a shipping box instead.
4. Check carrier dimensional weight. UPS and FedEx charge by dimensional weight when a package is light for its size. Trimming even half an inch from each side can lower shipping costs on every order.

Popular mailer box sizes and what fits

• 6 × 4 × 2 in: jewelry, cosmetics, small accessories, sample kits.
• 8 × 6 × 2 in: skincare sets, socks, small candles, phone accessories.
• 9 × 6 × 3 in: the most popular all-rounder: candles, small apparel, beauty kits, gift sets.
• 10 × 8 × 4 in: T-shirts, books, subscription kits, larger candle sets.
• 12 × 9 × 4 in: hoodies, multi-product bundles, monthly boxes.
• 14 × 10 × 4 in and up: shoes (low profile), larger apparel bundles, home goods.

Any custom size is available. We do not charge extra for a non-standard size because every mailer is die-cut to order anyway.

Mailer box pricing: what drives the cost

Every mailer box price is built from the same handful of factors. The price table near the top of this page shows how quantity alone changes the unit price; here is what else moves it.

1. Quantity. Setup work (plates, dies, machine make-ready, proofing) is spread across the run, so the per-box price falls quickly up to about 1,000 units and keeps falling more slowly after that.
2. Size (board area). A mailer's flat blank grows with every inch, and the double side walls make height especially expensive. Reducing height by an inch often saves more than reducing length.
3. Board grade. B-flute costs more than E-flute; white liner costs more than kraft.
4. Print coverage and sides. Printing outside only is cheapest. Inside printing adds a second print pass.
5. Finishes. Lamination, spot UV, foil and inserts each add a per-unit cost and, for foil and embossing, a one-time die charge.
6. Shipping. Mailers ship flat, but freight still depends on total weight and destination.

Here are estimated prices for a larger 12 × 9 × 4 in mailer in B-flute kraft with printing inside and out, for comparison with the standard size above:

Seven ways to lower your mailer box price

• Order 500 to 1,000 units instead of 100 to 250 if you have the storage. The per-unit saving is usually 30–50%.
• Right-size the box. Every square inch of board you remove reduces material cost and dimensional weight.
• Use one hero finish. A great structure with one finish beats three competing finishes.
• Print the inside in one color instead of full color.
• Choose kraft for a natural look at a lower board cost.
• Standardize across products. One mailer size for several products means larger runs and simpler packing.
• Plan ahead. Rush production costs more; standard lead times keep your price lower.

Our packaging cost guide and the Packaging Cost Calculator let you compare options side by side.

Designing artwork for mailer boxes

A great mailer design is planned around how the box is opened, not just how it looks closed. Think in sequence: the doorstep, the lift of the lid, the inside reveal, then the product.

Design principles that work

• One dominant element outside. A large logo, a bold pattern or a single word reads instantly from across a room and in social media photos.
• Save the surprise for the inside. A contrasting color or a short message on the inside lid ("Hello, you." or "Made for you") delights for very little cost.
• Respect the folds. Keep critical text and logos at least 1/8 in away from crease lines and 1/8 in inside cut lines. Extend background colors 1/8 in past the cut line (bleed).
• Mind the rolled edges. The double side walls mean the inside face of the side wall is printed on the outside artwork. Your dieline shows which panels flip.
• Plan the shipping label. If boxes ship without an outer carton, leave a clean area on the lid or base for the carrier label so it does not cover your logo.

Note: If your mailer will ship as-is (no outer carton), carriers will scuff it. Matte coatings hide scuffs better than gloss; dark full-coverage colors show scuffs more than light ones.

File setup checklist

1. Design on the dieline for your exact size and board thickness.
2. Use CMYK color mode (or name Pantone spot colors).
3. Keep images at 300 ppi at final size; vector logos are best.
4. Convert fonts to outlines or include them.
5. Put special finishes (spot UV, foil) on separate layers as 100% spot colors.
6. Export a print-ready PDF with bleed.

Not sure your files are ready? Send what you have. Free artwork checks come with every quote, and our artwork guidelines cover everything in detail. You can also test a logo's resolution instantly with the Artwork Checker.

Mailer boxes by industry

Mailers are versatile, but each category has its own priorities:

• Apparel and fashion: shallow, wide mailers with tissue paper and a sticker seal. B-flute for hoodies and bundles. See apparel boxes.
• Beauty and skincare: compact E-flute mailers with a die-cut insert to stop bottles moving. See cosmetic boxes.
• Candles: B-flute with a snug insert around the glass jar; avoid big air gaps. See candle boxes.
• Subscription boxes: consistent outside design, a rotating inside print or insert card each month. See subscription boxes.
• Food and coffee: mailers for gift sets and samplers, with food-safe coatings if product contacts board. See coffee and tea boxes.
• Electronics and gadgets: E-flute mailer with a fitted insert and a clear opening direction. See electronics boxes.
• Corporate gifting and PR kits: premium print inside and out, often with a foil logo and an insert. Compare with magnetic closure boxes for the top tier.

Mailer boxes and sustainability

A corrugated mailer box is one of the most recyclable packaging formats available. Corrugated board is accepted in curbside recycling across nearly all of the United States, and the industry reports some of the highest recovery rates of any packaging material. To keep your mailers easy to recycle:

• Prefer paper-based finishes. Aqueous coatings recycle easily. Heavy plastic laminations and large foil areas can complicate recycling in some facilities.
• Use paper inserts (paperboard or corrugated) rather than foam where possible.
• Choose recycled-content board when available, and right-size to use less material overall.
• Make claims carefully. Statements like "recyclable" should follow the FTC Green Guides. Our sustainable packaging guide explains how to word them.

Mailer box variations

The classic roll end tuck front is only the starting point. These variations are all made from the same family of dielines and can be quoted the same way:

• Front tuck with dust flaps (standard). The version on this page. Ears on the lid tuck inside the side walls to keep dust out and make the lid sit flat.
• Double tuck mailer. Tuck flaps on both the front and the sides of the lid for extra security on heavier contents. A good choice when boxes are handled roughly or reused for returns.
• Mailer with a tear strip. A perforated zipper strip runs around the front so the customer pulls a tab to open it. It doubles as tamper evidence and is popular for subscription and supplement programs.
• Mailer with handle. A die-cut handle in the back wall and lid turns the mailer into a carry box for bakery, gift and event kits.
• Window mailer. A die-cut window in the lid, optionally patched with clear film, shows off colorful contents. Windows reduce stacking strength slightly, so they suit lighter kits.
• Cereal-style or shoe-style mailer. A taller variation with a hinged lid and full-height side walls, used for footwear and bulkier apparel.
• Mailer with return features. A second adhesive strip on the tuck flap lets customers reseal the box for returns, which reduces packaging waste and support tickets.

If you have a reference box you like, send photos or measurements with your quote request and we will match the structure.

Packing and assembly tips

A mailer that is easy to assemble saves real money on your packing line. A trained packer can fold a standard mailer in a few seconds; these tips keep it that way:

1. Pre-fold a batch. Folding 20 to 50 boxes in a row before packing is faster than folding each one as you go.
2. Fold the side walls first, then lock them into the base slots. The double walls should sit flush; if they bulge, the inside dimensions or board grade may need adjusting.
3. Place inserts before products. Drop the insert in, then seat each product so nothing moves when the box is tilted.
4. Do the shake test. Close the lid and shake gently. If you hear movement, add a tissue wrap or adjust the insert.
5. Store flat and dry. Keep flat-packed mailers off concrete floors and away from humidity. Damp corrugated board loses a large share of its compression strength and can warp.
6. Rotate stock. Use older boxes first so colors and board stay consistent across shipments.

Mailer box vs. other box styles

Ordering checklist for custom mailer boxes

Use this list to get an accurate quote on the first try:

• Inside dimensions (L × W × H) and what goes inside
• Board: E-flute or B-flute; white or kraft
• Printing: outside only, or outside and inside; number of colors or full color
• Finishes: coating, lamination, spot UV, foil, insert
• Quantities: ask for two or three price breaks (for example 500, 1,000 and 2,500)
• Delivery ZIP code and target date
• Artwork status: print-ready files, logo only, or design needed

Common mailer box mistakes to avoid

1. Sizing to the product instead of the packed product. Tissue, inserts and cards take space. Measure the full kit.
2. Ignoring board thickness. Inside dimensions shrink if the board gets thicker. Always confirm the dieline after changing material.
3. Too much empty space. Oversized boxes cost more, ship at higher dimensional weight and let products move and break.
4. Text on fold lines. Folds crack ink and distort text. Keep a safe margin.
5. Bright colors on kraft. Kraft mutes color. Use white board for vivid brand colors.
6. Skipping the proof. Always approve a 3D or physical proof. It is free with every order.
7. Forgetting the label area. If boxes ship without an outer carton, plan where the shipping label goes.

Related guides

GuideE-commerce shipping packagingHow to package e-commerce orders so they arrive intact: board strength, void fill, inserts, drop testing, Amazon FBA prep and branded unboxing on a budget. GuideUnboxing & brand designHow to design packaging that sells and gets shared: brand hierarchy, color, typography, the unboxing sequence, inserts and low-cost upgrades that matter. GuideBox sizing & DIM weightHow to measure inside vs outside box size, choose clearances, calculate UPS, FedEx and USPS dimensional weight, and right-size boxes to cut shipping costs. GuideHow much custom packaging costsRealistic 2026 price ranges for custom mailer, shipping, carton, rigid and pouch packaging, what drives cost, and proven ways to lower your unit price.

Not sure whether you need a mailer or a regular shipping box? Read mailer box vs shipping box.

What finishes and add-ons cost

Estimated extra cost per unit at 1,000 units when you add one finish to a 9×6×3" mailer box (base estimate $1.06). One-time tooling such as foil and embossing dies is already spread across the run in the per-unit figure and listed separately for reference.

How mailer boxes compare with similar styles

Estimated unit prices at 1,000 units for each style at its most popular size, full-color print, delivered within the contiguous US, so you can weigh mailer boxes against the alternatives customers often consider.

Learn about these materials

• E-flute corrugated, white
• E-flute corrugated, kraft
• B-flute corrugated, kraft

How to order mailer boxes

1. 1Request a quote

   Tell us the style, size, quantity and artwork you have. Use the form or the live estimator.

2. 2Free design & dieline

   We send a dieline for your exact size, check your artwork and help with layout at no charge.

3. 3Approve your proof

   Review a digital 3D proof (and an optional physical sample) before anything is printed.

4. 4Production & QC

   Your boxes are printed, finished, die-cut and inspected against the approved proof.

5. 5Delivered to your door

   Shipped flat-packed with tracking to any address in the contiguous US.

Written and reviewed by the CustomPacka Packaging Team · Updated October 21, 2026