Custom
Mailer Boxes
Engineered.
Precision-engineered corrugated mailer boxes for e-commerce brands, DTC companies, and subscription services. Order 1 box or 10,000 — no minimum, no setup fees, 48-hour quote with a free 3D mockup.
What is a custom mailer box?
A custom mailer box is a corrugated cardboard box engineered for direct-to-consumer shipping — serving simultaneously as the product container and the shipping container, with no external packaging required. Unlike a plain shipping box sealed with tape, a mailer box uses a self-locking dust-flap and tuck-tab closure system that assembles without adhesive.
The defining characteristic of a custom mailer box is that it is printed on both the exterior and interior surfaces, making the opening moment a deliberate brand experience — not an afterthought. For DTC e-commerce brands, subscription services, and direct-gifting businesses, the custom mailer box is the first physical brand interaction your customer has with your product.
Custom mailer boxes are manufactured from corrugated fiberboard — typically E-flute (1.5mm) for lightweight DTC shipping, B-flute (3.2mm) for heavier products requiring added crush resistance, or C-flute (4mm) for maximum structural protection. The substrate is then printed using digital CMYK or flexographic printing processes, and finished with a surface treatment such as matte laminate, gloss laminate, or soft-touch coating.
The custom mailer box is the most versatile format in the CustomBoxesLabs catalogue. It is used by Shopify brands scaling from their first 10 orders to enterprise fulfillment operations shipping 100,000+ units per month — and unlike every competing supplier, we produce them from a single unit with no minimum order commitment.
Custom Mailer Box Specifications
Full technical specification range for custom mailer boxes at CustomBoxesLabs. All dimensions are interior measurements. Custom sizes available within manufacturing tolerances — submit your exact dimensions in the quote request.
| Specification | Options / Range | Notes |
|---|---|---|
| Flute grade | E-flute (1.5mm) · B-flute (3.2mm) · C-flute (4mm) | E-flute recommended for most DTC orders under 5 lbs |
| Board composition | Single-wall corrugated | Double-wall available on request for heavy items |
| Length (interior) | 3″ – 24″ | Custom dimensions available within range |
| Width (interior) | 2″ – 18″ | Width must be ≤ length |
| Depth (interior) | 1″ – 12″ | Shallower depth = lower dimensional weight |
| Print area | Exterior + interior (all panels) | Includes dust flaps and tuck tabs |
| Print process | Digital CMYK · Flexographic (1–2 color) | Digital for full-color; flex for cost-optimized high-volume |
| Color mode | CMYK · Pantone (PMS) available | Submit artwork as CMYK; PMS matching quoted on request |
| Artwork resolution | 300 DPI minimum at print size | Vector files (.ai, .pdf) preferred for logos and type |
| Bleed | 0.125″ (3mm) all edges | Dieline template includes bleed guides |
| Surface finish | Matte laminate · Gloss laminate · Soft-touch · Spot UV · Uncoated | Soft-touch is premium; adds ~3–5 day lead time |
| Substrate color | White coated (standard) · Natural kraft | White substrate recommended for full-color CMYK fidelity |
| Closure type | Self-locking tab (standard) · Magnetic closure (premium) | Self-locking tab requires no tape; magnetic adds cost |
| Add-ons | Window cut-out · Ribbon pull · Custom insert · Tissue paper lining | Add-ons quoted individually; note requirements in quote request |
| Sustainability | FSC-certified board · Soy-based inks · 100% recyclable | FSC certification available on all orders; note in quote |
| Minimum order | 1 unit | No setup fees · No MOQ · No penalty for small orders |
| Lead time | 10–15 business days (standard) · 5–7 days (prototype) | Rush options available — note deadline in quote |
| Shipping | USA-wide · Flat-packed for freight efficiency | Shipping cost included in your 48-hour quote |
Choosing the Right Flute Grade
The corrugated flute grade determines your mailer box's structural performance, weight, print surface quality, and shipping cost. Selecting the correct flute is the single most important structural decision in the spec process.
The most popular flute grade for branded DTC mailer boxes. E-flute provides a smooth, consistent print surface that delivers the sharpest full-color CMYK results — critical for brand-forward packaging. It is lightweight, flat-packing efficiently, and its 1.5mm wall keeps dimensional weight low, reducing carrier surcharges on lightweight shipments.
B-flute offers significantly higher crush resistance and stacking strength than E-flute, making it the correct choice for heavier products, glassware, ceramics, or any item requiring additional impact protection during transit. The coarser flute structure slightly reduces print resolution compared to E-flute — acceptable for most designs, but logo-heavy artwork benefits from E-flute.
C-flute is the heaviest-duty single-wall corrugated option, providing maximum compression strength and puncture resistance. It is used when a mailer box must function as its own protective outer carton for dense or fragile products. The thicker wall adds weight and dimensional volume — factor this into your carrier cost calculations before specifying C-flute for lightweight items.
Print & Surface Finish Options
The surface finish determines how your artwork feels and reads in natural light — and signals perceived quality before the box is even opened. Choose the finish that aligns with your brand positioning.
Flat, non-reflective surface with a premium tactile quality. Matte finish reduces fingerprinting and creates a clean, modern brand aesthetic. Most popular finish for lifestyle, wellness, and DTC brands.
High-sheen reflective surface that makes CMYK colors vibrate with intensity. Gloss finish maximizes color saturation — reds, blues, and greens read 15–20% more vivid than on matte stock. Fingerprints are visible on dark backgrounds.
A velvety, rubberized coating that creates a distinctly premium tactile experience at the moment of opening. Soft-touch is the finish choice for luxury-positioned brands that want packaging to communicate product value before the box is opened. Adds 3–5 days to lead time.
A selective gloss coating applied only to specific design elements — logos, brand marks, or typographic details — on a matte-laminated background. Creates a dramatic contrast between glossy and matte areas. Requires a separate spot-UV dieline layer in your artwork file.
Custom Mailer Boxes by Industry
The custom mailer box format serves every vertical that ships direct-to-consumer — from Shopify-native startups to established subscription brands. The structural requirements, ideal flute grade, and recommended finish vary by application.
For Shopify, WooCommerce, and DTC brands shipping direct to consumers. E-flute custom mailer boxes are the industry standard — lightweight, structurally sound for USPS and UPS shipping, and printable on all exterior and interior panels for a full brand experience at the moment of delivery.
E-commerce packaging guideSubscription brands require mailer boxes that create a consistent, repeatable unboxing ritual — one that subscribers share on social media and that justifies monthly retention. Full interior print, custom insert fitment, and a distinctive exterior design compound into measurable churn reduction over a subscriber's lifetime.
Subscription packaging guideBeauty brands shipping skincare, makeup, and personal care products use custom mailer boxes with soft-touch laminate and spot UV finishes to communicate premium quality before the product is seen. For fragile cosmetic items, B-flute provides the additional structural protection required without sacrificing exterior print quality.
Cosmetics packaging guideArtisan food brands, coffee roasters, hot sauce companies, and specialty food DTC businesses use custom mailer boxes as the primary shipping container for their product. Non-food-contact corrugated is appropriate for most packaged food applications. For products requiring food-safe inner packaging, we recommend pairing the mailer box with a food-grade folding carton insert.
Food packaging guideHow to Order Custom Mailer Boxes
Three phases from spec submission to delivery. No hidden steps, no surprise charges, no guesswork.
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Submit your spec
Use our quote request form to submit your interior dimensions (L × W × D), flute grade preference, quantity, finish, and any add-ons. If you're unsure about any specification, leave a note — our team will provide a recommendation in your 48-hour quote. No artwork required at this stage.
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Review your mockup & quote
Within 48 hours, you receive a detailed itemized quote and a free 3D digital mockup showing your box dimensions, finish, and a dieline template for your artwork. Upload your print-ready artwork file (or apply it to the provided dieline template). Our pre-press team reviews artwork for bleed, resolution, and color-space accuracy before confirming production.
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Production & USA delivery
Approved orders enter the production pipeline within 24 hours. Standard lead time is 10–15 business days from artwork approval. Your custom mailer boxes ship flat-packed directly to your facility, warehouse, or fulfillment center, USA-wide. Tracking information is provided when your order ships.
Mailer Box vs Shipping Box vs Rigid Box
Not every product needs a custom mailer box. Use this comparison to identify the correct packaging format for your product, shipping method, and brand positioning. Full comparison: Mailer Box vs Shipping Box — Decision Guide.
| Feature | Custom mailer box | Shipping box (RSC) | Rigid box |
|---|---|---|---|
| Primary purpose | Brand + shipping | Protective transit | Brand + retail display |
| Closure type | Self-locking, no tape | Tape-sealed | Lid + base / magnetic |
| Print: exterior | |||
| Print: interior | |||
| Ships without outer packaging | |||
| Unboxing experience | High — branded interior | Low — plain interior | Highest — tactile premium |
| Cost per unit | Medium | Low | High |
| Ships flat | |||
| Min. order at CustomBoxesLabs | 1 unit | 1 unit | 1 unit |
Mailer Box Guides & Resources
Everything you need to spec, design, and order custom mailer boxes — before submitting your quote.
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