Here are some recommendations for where to buy stock packaging:
Bubblefast: Bubblefast is a fantastic resource for affordable shipping supplies. Find boxes, poly mailers, shipping tape, and packing materials.
Aviditi: Aviditi is a great supplier through Amazon, and if you have a Prime account, you get free shipping for products from this company. You'll find boxes, poly mailers, packing materials, tape, etc.
This is a great resource for eCommerce businesses just getting started, with about 25 units per order at super affordable prices.
UCGOU: UCGOU is all about mailers, poly bags, and more. They sell through Amazon and offer Prime, so you'll get free shipping if you're a Prime member.
There's a lot of variety in size, padding, and color, and roughly 50-100 units per order at low prices.
Where to get free boxes and envelopes for your shipments
If you don't want to spend money, you can get free packaging from USPS and UPS! Here's more info on where to pick that up.
USPS® Priority Mail boxes and envelopes
Free Boxes on the USPS Website: You can order boxes and envelopes for Priority Mail shipments on the USPS website. They're totally free, and USPS will deliver them right to your door!
Paying for the Service Marked on Your Packaging: Note that whenever you're making USPS labels, you need to pay for the exact Priority Mail service marked on your box or envelope if you're using one of those free USPS packaging options.
UPS® Express packaging
Free UPS Express Boxes and Envelopes: Similar to USPS, UPS offers free UPS express boxes and envelopes that you can pick up on their website.
While you don't need to pay for them, you'll need to create a UPS.com account to place your order.
Want to customize your packaging? Here are some options:
1) If You Only Need 200-500 Boxes: For smaller box quantities, you're best off with one of the online sources, like:
Quick But Expensive Solutions: These companies give you the quickest solutions, but the unit cost-per-box will be pretty expensive with limited quantities like this, likely in the $2 to $5 range.
2) If You Need Thousands of Boxes: For larger box quantities, it's usually best to go local. Since boxes are such a fundamental need for most industries, almost every city has cardboard manufacturers you can find in the phonebook or a Google search. They'll offer stock box sizes, and can also make custom boxes to exact specifications.
Work With Packaging Industry Middlemen: There are also lots of middlemen in the packaging industry who work with multiple manufacturers. These companies can warehouse boxes, offer just-in-time delivery, monthly payment terms, etc:
Two things you need to buy upfront with custom packaging
When you create a custom box, there are 2 things you'll have to buy upfront:
The Die: This is what "cuts" your box shape out of the raw cardboard.
The Printing Plates: These allow you to custom print your design on cardboard.
Costs of Custom Packaging: These initial costs usually run from $2-5k on top of any design work, and then you'll be looking at a minimum order requirement of 5-10k boxes. That said, unit cost-per-box will be much less because of the quantity, typically in the 50 cents to $2 range.