If you're selling on Poshmark Canada, eBay, Depop, or Vinted, the right bubble mailer size can mean the difference between a clean profitable shipment and a refund request because something arrived damaged. This guide covers exactly what to use for clothing, trading cards, electronics, shoes, and small items — plus where Canadian sellers actually buy in bulk.
The numbered sizing system (#000 through #7) isn't intuitive. Here's what Canadian resellers actually use for common item categories:
| Item | Best Size | Interior Dimensions (approx.) | Notes |
|---|---|---|---|
| Trading cards (sleeved) | #0 or #00 | 6×10" or 5×10" | #0 fits a PWE + toploader stack comfortably; #00 for light packages |
| Funko Pops (single) | #4 | 9.5×13.5" | Tight but works for standard Funko; large or holiday editions need #5 |
| T-shirts, folded | #4 or #5 | 9.5×13.5" or 10.5×16" | #4 for a single tee; #5 for a hoodie or multiple items |
| Jeans / pants | #6 or #7 | 12.5×19" or 14.25×20" | Fold tight; a single pair of jeans folded to 12×18" fits a #6 with room |
| Books (paperback) | #2 or #3 | 8.5×11" or 8.5×14.5" | #2 for standard paperbacks; #3 for larger trade paperbacks |
| Small electronics (phone) | #2 or #3 | 8.5×11" to 8.5×14.5" | Wrap in extra bubble wrap first; the mailer adds a second layer |
| Shoes (single, boxless) | #7 | 14.25×20" | Shoes with the box need an actual box — bubble mailers aren't rigid enough |
| Jewelry / small accessories | #000 | 4.5×8" | Cheapest option; fine for necklaces and rings in a small bag |
This is where a lot of Canadian resellers leave money on the table. Canada Post's Lettermail and Parcel rates have specific weight thresholds, and the bubble mailer itself adds weight you need to account for.
A standard poly bubble mailer weighs roughly 15–30g depending on size. A kraft bubble mailer runs heavier — 30–50g. If your item is right at the edge of a weight tier, the mailer type can push you into the next pricing bracket.
For clothing specifically: Poshmark Canada uses their own prepaid labels, so the mailer weight doesn't affect your label cost directly. But eBay and Depop sellers using Canada Post pay by weight, and getting under 500g (for Expedited Parcel) versus under 100g (for Regular Parcel Small) is a meaningful cost difference.
Short version: poly for most resellers, kraft if your buyer expects premium packaging.
Poly bubble mailers (the shiny/metallic ones) are lighter, water-resistant, and cheaper per unit in bulk. They're the default for Poshmark and eBay shipments across Canada. The downside is purely aesthetic — they look utilitarian. If you're selling vintage or high-end items and presentation matters to your brand, kraft gives a warmer, more intentional look.
White poly mailers photograph better if you include a photo of your packaging in listings. Gold or silver metallic poly mailers are common and functional but not distinctive. It's a minor thing, but regular buyers notice the details.
The r/poshmarkcanada and r/CanadaPost communities have settled on a few clear answers for this:
Amazon.ca is the most convenient option for most sellers. Buying 50–100 units at a time with Prime shipping, no minimum order, reliable stock. Per-unit cost is higher than Uline but you're not committed to a case of 500 items that might not fit what you're shipping. Good brands to look for: UCGOU, METRONIC, Tufpak.
Uline Canada (uline.ca) ships from Canadian warehouses and has the best per-unit pricing at volume — around $0.25–0.55 per unit for standard poly mailers when you buy a case. Minimum order is typically a full case (100 units), and their shipping on small orders can add up. Worth it once you're shipping 20+ items a week and know exactly which sizes you need.
Packends.com comes up regularly in Canadian reseller communities as a cheaper option than Uline for smaller quantities. Worth checking their current pricing against Amazon.ca.
Staples Canada is convenient for emergency restocking but expensive per-unit. Fine for one-offs, not for bulk.
Seal quality. A bubble mailer with a weak self-seal strip is a liability — especially if your package sits in a Canada Post depot for a few days. Pull the seal on a few from any new batch before you ship with them. If they peel apart with light pressure, return the batch.
Label adherence. Some cheaper mailers have a surface that doesn't hold Canada Post labels well in cold weather. Shipping in January in Manitoba or Saskatchewan? Test your labels. A printed Canada Post label peeling off mid-transit is a nightmare.
Stacking space. If you're shipping clothes to multiple buyers on the same day, having the right size mailers already on hand beats cutting corners with whatever's available. Buy a reasonable supply of your two most-used sizes and reorder before you run out.