Cornerstone reference page · Updated 2026-04-29 · ~85 SKUs indexed · Built from the live Packrift catalog.

2026 Best-Value Poly Mailer Index — Every Size, Mil Thickness, and Color Ranked by Cost

A live, sortable index of 69 active poly mailer SKUs from the Packrift catalog — ranked by cost-per-each, cross-referenced against per-size benchmarks, with a calculator that picks the right SKU for your shipping volume. Lowest per-each in this index: $0.0439/each for 6x9" white 2.5 mil at case-of-1,000.

Executive summary — 5 takeaways

What's a poly mailer + when it's the right format

A poly mailer is a thin, flexible polyethylene (LDPE) envelope with a peel-and-seal adhesive strip across the opening. It has no internal cushioning — the protection comes from the film's tear, puncture, and stretch resistance, not from a bubble or foam liner.

Poly mailers are the right format when:

• The product is non-fragile and soft — apparel, fabric, swim/activewear, hats, light shoes in their original boxes, towels, bedding, plush, books in dust jackets.
• The product is already in retail packaging that can take light pressure (a folded shirt in a polybag, a paperback in a chipboard sleeve, a coffee bag in a foil pouch).
• You ship at SMB-to-mid volume and dim weight matters — poly mailers reduce dim weight by 20–60% vs an equivalent box, which directly cuts UPS / FedEx Ground costs at all common zones above zone 3.
• You want a soft, low-rigidity carrier that conforms to the product instead of leaving void fill space. Less material per shipment, cheaper carrier rates, lower returns rate from "wrong size box" rattling.

Poly mailers are not the right format when:

• The product is rigid and breakable (glass, ceramics, electronics) — use a corrugated box plus internal cushion. See our bubble-mailer-vs-poly-mailer cost calculator.
• The product needs hard impact protection (bound book, framed print) — use a stayflat mailer or board-protected envelope.
• The product has hard edges or corners that can puncture 2–3 mil film — use bubble or stepped padding.

Field rule: if the product survives being dropped flat from belt height onto concrete inside its retail packaging, it's a poly-mailer candidate. Almost all softgoods clear this bar. Almost no rigid product does.

The 7 most-popular poly mailer sizes

The seven sizes below cover the overwhelming majority of SMB ecommerce poly-mailer volume — apparel, accessories, books, beauty, light hardware, replenishment subscriptions, and oversized softgoods. Each row shows the lowest case-of-100/500/1000 we found in the Packrift index, with min/median/max per-each across all SKUs in that size class.

Per-each computed as case price ÷ case quantity. "Min" is the absolute lowest cost-per-each Packrift offers for that size class, including bulk case-of-500 and case-of-1000 SKUs. "Median" is more representative of what most buyers actually pay because case-of-100 inventory dominates the SKU count.

Why these seven sizes dominate

• 6x9 — jewelry, small accessories, smartphone cases, single t-shirts (folded), beauty samples. Cheapest envelope in the catalog ($0.0439/each at case-of-1000).
• 7.5x10.5 — paperback books, single t-shirts (folded), small zippered pouches, mid-size beauty/skincare. Sometimes called "10.5x7.5" — same size.
• 9x12 — single shirts, leggings, swim, light scarves, mid-size books, A4-sized printed material.
• 10x13 — the workhorse. Apparel sets, hoodies, multi-shirt orders, Amazon FBM standard. 11 SKUs in this size class — the most in the index.
• 12x15.5 — replenishment subscriptions, larger apparel sets (jackets, hoodies + tee + pants), bedding, towels.
• 14.5x19 — heavy apparel, jackets, multi-piece returns consolidations, pillow inserts, plush, blankets.
• 19x24 — oversized softgoods, comforters, big jackets, pillows, two-pillow sets. The largest "single envelope" size most carriers will accept without surcharge.

The master poly mailer SKU table

Every active priced poly mailer in the Packrift catalog (69 SKUs), filterable by size, mil thickness, color, expansion (gusseted vs flat), and case quantity. Default sort: $/each ascending. Click any column header to re-sort.

Pricing reflects the live Packrift Shopify catalog as of 2026-04-29. Case quantities and per-each derive from SKU title parsing. View any product page for verified pricing, dimensions, and specs.

Per-size cost benchmarks

Cross-referenced against the 2026 Bubble vs Poly Mailer Cost dataset (1,196 mailer SKUs across the broader Packrift catalog), here's how the seven dominant poly-mailer sizes price:

Two readings to take away from this table:

1. Spread widens with size. 6x9 max is ~3× the min. 14.5x19 max is ~2.5× the min. The pattern is consistent: the bigger the envelope, the more you pay for "premium" features (heavier mil, branded surface, color, smaller case quantities).
2. Median is much higher than min for almost every size. That's because the catalog has many more case-of-100 SKUs than case-of-500/1000 SKUs. If you can commit to a case-of-500 or case-of-1000 buy, you skip the median and land near the min — where the real value is.

For a deeper economic view of when bubble cushioning actually pays off vs flat poly, see Bubble Mailer vs Poly Mailer Cost (2026) — the per-each premium for bubble runs about 2–3× the equivalent poly mailer at the same size.

Best by use case — recommended Packrift SKUs

Below are eight specific poly-mailer recommendations from the Packrift catalog, each chosen for a real use case rather than a generic "best overall." Every recommendation is a current active SKU at the price shown.

Mil thickness decision matrix

"Mil" is one-thousandth of an inch. 2.5 mil is roughly the thickness of a sheet of standard printer paper folded in half. 3 mil and 4 mil step up from there in 20–60% increments per step.

For a deeper framework, see Mil Thickness Decoded (R8) — covers the full break-even between film weight, carrier damage rates, and customer-returns cost.

Most-common mistake: over-spec'ing mil. We see DTC brands buy 4 mil "for premium feel" when the product never warranted more than 2.5 mil — paying 3–6× per envelope for ~zero customer-perceived value. The unboxing premium comes from opacity, color, and surface print, not film thickness.

Color choice math — does it matter?

Three things drive the white/clear/colored decision:

1. Brand perception. Opaque white reads premium against the "default plastic" expectation. Clear reads logistics/wholesale. Colored (especially black, navy, or brand-matched) reads boutique or DTC.
2. Privacy. Clear poly mailers reveal the product. For most apparel that's fine. For adult product, gifts, or anything where the recipient is not the buyer, opaque (white or colored) is mandatory.
3. Cost. In the Packrift catalog: white median $0.2468/each (n=45) — but skewed by case-of-100 SKUs in the upper bound; clear median $0.1972/each (n=9); colored (black/blue/red/yellow/pink) all priced $0.2998/each at the 10x13 size class. So the color premium vs same-size clear at 10x13 case-of-100 is roughly 0% — they trade at parity. The premium shows up in lack of bulk case quantities for colored: there's no case-of-500 colored SKU in the catalog right now, so a high-volume buyer pays the case-of-100 cost no matter what.

Decision rule: if you ship more than 200 packages/month, default to white (opaque + bulk-case pricing available). Use clear only if your product is decorative or you want the recipient to see it before opening (rare). Use colored only if it's a deliberate brand statement and you're under ~150 packages/month.

Embedded recommender — pick the right poly mailer

Logic: we pick the smallest size that fits your product longest dimension + 2" padding, choose the cheapest case quantity that covers ≥1 month of shipments, then bias toward white opaque if branded experience is medium/high. Switching savings = monthly spend on default 10x13 white case-of-100 minus monthly spend on the recommended pick.

Bulk procurement

If your monthly volume is north of ~1,000 mailers, the case-of-500 and case-of-1000 SKUs in this index aren't the end of the value curve — they're the start. Build a quote for pallet-level pricing and we'll match or beat any line-item price in this table:

• Bulk cart builder → — assemble a multi-SKU pallet quote, get freight included on qualifying carts, and lock pricing for 30 days.
• Browse all Packrift poly mailers → — the live collection page (full inventory, including SKUs not yet indexed in the table above).

Quick rule: if you're buying more than 12 cases-of-100 per quarter at any size, switch to a single case-of-500 or case-of-1000 SKU at that size — the per-each drops 30–50% and your storage footprint shrinks (one carton instead of twelve).

The "right size beats more cushion" rule — when poly beats bubble

One of the highest-leverage packaging decisions is choosing the smallest envelope that contains your product without forcing it. Most buyers default to "one size up + bubble" because it feels safer. The math says otherwise.

Take a single folded T-shirt:

• Right-sized 9x12 white poly mailer 2.5 mil, case-of-1000: $0.0878/each.
• Same shirt in a 9x12 #4 kraft bubble mailer at the equivalent case quantity: roughly $0.20–0.30/each (see R1 benchmarks).
• Net savings on poly: roughly $0.12–0.21/shipment, and dim weight drops ~30% because the envelope flattens around the shirt.

The poly mailer wins on cost, dim weight, and material footprint — and the shirt is just as protected, because a folded T-shirt does not need cushioning. The cushion was solving a problem that didn't exist.

When does the bubble premium pay off?

• Hardware with sharp edges that can puncture poly film.
• Glass, ceramics, electronics, anything fragile and rigid.
• Multi-item shipments where items can chafe each other in transit.
• Cold-weather routes where film can become brittle (rare; LDPE handles −20°F fine, but polypropylene gets fragile).

For everything else, "right-size + 2.5 mil poly" beats "+1 size + bubble" on every dimension — cost, carrier weight, and customer experience. The cushion-bias is a packaging-industry artifact, not a logistics requirement.

Common buyer mistakes

1. Over-buying bubble when poly works. Default to bubble for "safety" then pay 2–3× per shipment. If your product is non-rigid, poly is the right answer.
2. Under-spec'ing mil for hardware shipments. 2.5 mil is fine for clothing. It's not fine for tools, multi-piece returns, or anything with sharp metal edges. Step to 4 mil or use a polywoven envelope.
3. Picking color without margin context. Colored mailers cost the same per-each as white at case-of-100 — but you can't bulk-buy colored at case-of-500/1000 in our catalog. If your monthly volume is 500+, you'll pay double for the color.
4. Buying case-of-100 when monthly volume is 500+. The case-of-500/1000 lower per-each price pays back the extra cash up front in 4–8 weeks of normal shipping. Storage cost: one extra carton.
5. Mixing six "small" SKUs instead of standardizing on three. Buyers who consolidate to ~3 SKUs (e.g. 9x12, 10x13, 12x15.5) cut their procurement and inventory tracking complexity by ~50% with no protection downgrade for any product class.
6. Choosing oversized "to be safe" with void fill. A 12x15.5 stuffed with paper to protect a 9x12 product costs more in mailer + void fill + dim weight than just buying the 9x12. Right-size first.

Methodology appendix

• Source. Packrift Shopify catalog (products.json), filtered to active priced SKUs as of 2026-04-29.
• Filtering. SKUs included if title contains "poly mailer" (case-insensitive). Excluded: bubble mailers, document envelopes, packing list envelopes, poly tubing, shrink wrap, and standalone label SKUs.
• Parsing. Size, mil, case quantity, color, and expansion (gusseted vs flat) parsed from product titles via regex. Per-each = case price ÷ case quantity. Where case quantity not explicit, defaults to 100 if "case" appears in title.
• Aggregates. Per-size and per-mil stats use n, min, max, mean, and median across all matching SKUs. Color cuts use the same.
• Recommender logic. Inputs: product longest side, monthly volume, branded-experience priority. Output: smallest size that fits product + 2" padding, cheapest case quantity covering ≥1 month, biased toward white opaque if branded priority is medium or high.
• Cross-reference. Per-size benchmarks cross-checked against the R1 dataset (1,196 mailer SKUs catalog-wide) and 2026 packaging cost benchmarks (2026-packaging-cost-benchmark).
• Internal-link references. Poly mailers collection, Bubble vs poly cost, Mil thickness decoded, Bulk cart builder, Packaging glossary.
• Limits. Per-each is sticker price; doesn't account for freight inbound, storage cost, or breakage rate. Buyers comparing across vendors should normalize to landed cost per shipment, not catalog per-each.

Built from the live Packrift catalog · 2026-04-29 · 69 active poly mailer SKUs indexed · Have a SKU we should add or a price correction? Email us at the address linked from any product page.