For any business that ships soft, non-fragile goods — apparel, accessories, linens, bedding, or subscription boxes — poly mailers are the default packaging choice for a reason. They’re lightweight, waterproof, tear-resistant, and cheap to ship compared to boxes. But the economics only work in your favor once you move from retail packs to true wholesale volume. This guide covers how B2B buyers should choose sizes, where poly mailers fit into different shipping workflows, and why one size in particular — 14.5×19″ — has become a go-to for apparel sellers shipping bulkier orders.

Why Poly Mailers Make Sense for B2B Shipping

Compared to corrugated boxes, poly mailers weigh a fraction as much, which keeps dimensional and actual shipping weight down — a meaningful saving when you’re shipping thousands of parcels a month. They’re also self-sealing, which speeds up a packing line considerably compared to taping a box shut. For wholesale buyers, the calculus usually comes down to three factors:

• Cost per parcel. Case and multi-case pricing on poly mailers is dramatically lower than what a retail 25- or 100-count pack costs per unit.
• Packing speed. Self-sealing strips let warehouse staff pack and seal an order in seconds, which matters at scale.
• Durability in transit. Quality poly mailers are waterproof and tear-resistant, protecting soft goods from rain, handling damage, and grime during transit — without the bulk of a box.

Matching Poly Mailer Size to Your Product and Use Case

The single biggest mistake B2B buyers make when ordering in bulk is guessing at size instead of matching it to what they actually ship. Buying the wrong size in a 500- or 1,000-pack case is an expensive mistake to repeat every month. Here’s how common sizes map to real shipping use cases:

• 6×9″ – 9×12″: small accessories, jewelry, phone cases, cosmetics, small stationery items.
• 10×13″: a widely used all-purpose size for T-shirts, single garments, and small multi-item orders.
• 12×15.5″: mixed apparel bundles, mid-weight garments, small home goods.
• 14.5×19″: bulkier apparel, hoodies and sweatshirts, multi-item bundles, and some bedding — covered in detail below.
• 19×24″ and larger: bedding sets, bulk apparel bundles, larger soft-goods orders, or B2B pallet-adjacent shipments.

Suppliers with a full size and color range — like the JiaroPack’s poly mailers — make it easier to standardize packaging across an entire catalog, since you can source every size and colorway from one wholesale price sheet instead of juggling multiple vendors.

Spotlight: 14.5×19″ Poly Mailers for Bulkier Apparel Orders

The 14.5×19″ size deserves its own mention because it sits at a sweet spot many apparel and soft-goods sellers grow into once their average order size increases beyond a single T-shirt or small accessory. At roughly 14 inches wide by 19 inches tall when laid flat, it has enough interior room for bulkier folded garments without stepping up to a size meant for full bedding sets.

Common Use Cases

• Hoodies and sweatshirts — most fold and fit comfortably with normal packing, without straining the seal.
• Multi-item apparel bundles — 3 to 6 folded tees, or mixed orders combining a top and bottoms, pack well in this size.
• Joggers, jeans, and coats that compress — heavier bottoms and compressible outerwear are a good match.
• Lightweight bedding — some throws or a twin sheet set can fit, depending on material thickness.
• Subscription boxes and multi-SKU orders — sellers bundling several products into one shipment often standardize on this size to avoid using a box.

One practical limit worth flagging for B2B buyers: heavy, structured winter coats are hit-or-miss in this size. A puffy jacket that compresses down can usually work, but a stiff, thick coat is often better suited to a larger mailer or a box, both to avoid stressing the seams and to keep a clean, tamper-resistant seal.

Format Options in This Size

Beyond the standard self-sealing bag, 14.5×19″ poly mailers are also commonly available with a carrying handle (useful for retail pick-up or local delivery workflows) and with a tear strip, which lets end customers open the parcel without scissors or a blade — a small detail that improves the unboxing experience for D2C brands. Buyers can review the full color and format range on JiaroPack poly mailers 14.5×19, which includes both standard and handled versions across more than a dozen colors.

How Bulk Pricing Works for Poly Mailers

Wholesale poly mailer pricing is almost always tiered by case quantity. A typical structure looks like this:

• 1 case — the baseline wholesale price, still meaningfully below retail per-unit cost.
• 2–4 cases — a moderate step-down in per-unit price, a common tier for growing sellers.
• 30+ cases — the deepest discount tier, aimed at established fulfillment operations with predictable monthly volume.

Case sizes vary by mailer size — smaller mailers often ship 1,000 per case, while larger formats like 14.5×19″ are commonly packed 500 per case. When comparing suppliers, always normalize to a per-unit cost rather than comparing case prices directly, since case counts differ across sizes and vendors.

Questions to Ask Before Placing a Bulk Order

1. What is the exact per-unit cost at your expected order volume, after any tiered discount?
2. Is the mailer genuinely waterproof, or just water-resistant — a meaningful difference for apparel shipped in wet climates?
3. Does the supplier offer a tear-strip or handled variant if your fulfillment process would benefit from it?
4. What colors and print options are available at your target size, and do they support custom branding?
5. What’s the lead time on a reorder, and is there a minimum reorder quantity?

Frequently Asked Questions

What size poly mailer should a B2B apparel seller start with?

Most apparel sellers standardize on two sizes: a smaller size like 10×13″ for single garments, and a larger size like 14.5×19″ for bundles, hoodies, and bulkier items. Starting with just these two covers the majority of order profiles before you need anything larger.

Are poly mailers actually waterproof?

Quality poly mailers are made from polyethylene film, which is inherently water-resistant to fully waterproof depending on thickness and seam construction. This is one of their key advantages over paper-based packaging for outdoor delivery conditions.

Can I ship a hoodie in a 14.5×19 poly mailer?

Yes, a standard adult hoodie typically fits comfortably in a 14.5×19″ mailer with normal folding. If you’re shipping a bulkier fleece-lined hoodie or bundling it with additional items, weigh a sample pack before finalizing size across your whole catalog.

How many poly mailers should a growing e-commerce brand order at once?

A common approach is ordering a 60–90 day supply based on current order volume, which is usually enough to reach a meaningful bulk discount tier without overcommitting cash to inventory before demand is fully validated.