I've been on the purchasing side of packaging orders for about six years now. I'd say eight, but my first two years were mostly chaos—so let's call it six years of learning, plus two years of making mistakes that I now document so others don't have to.

This checklist is for anyone who orders rigid plastic packaging—PET bottles, polypropylene jars, HDPE containers—and has ever received a shipment that was almost right but not quite. The kind of order where the color is off, the weight feels wrong, or the resin doesn't match the spec. I've personally overseen—and messed up—over 200 orders in that time. I've tracked my errors in a spreadsheet since 2022. The total cost of my documented mistakes? Roughly $14,000 in wasted materials, reprints, and expedited shipping.

Here's a 7-step checklist I now use before every order. It won't make you perfect, but it'll save you from the specific mistakes I've already made for you.

Step 1: Lock Down Your Material Specs — Not Just 'Plastic'

This sounds obvious, but you'd be surprised how often orders go wrong because the spec is vague. In my first year (2017), I ordered 5,000 PET jars for a beverage client. I specified 'PET.' Turns out, there are multiple grades of PET—some for cold fill, some for hot fill. Ours were cold-fill jars. The client needed hot-fill. Every single jar warped. $3,200 order, straight to scrap.

What to do:

Most packaging suppliers, including Amcor, provide detailed material specification sheets. If they can't give you one for the specific resin, that's a red flag.

Step 2: Get the Color Right on the First Try

Color matching is where I've seen the most frustration—and the most wasted budget. In September 2022, I approved a Pantone match for a client's logo on polypropylene jars. The sample looked great. The production run? A different shade entirely. The issue: the sample was on paper stock; the production was on opaque white PP. The substrate changed the color perception.

What to do:

I've learned to ask for three samples: one on the target material, one on a white card (for reference), and one with a gloss versus matte finish comparison. It costs a bit more upfront but saves thousands in reprints.

Step 3: Confirm Dimensions with a 'Fit Check'

Dimensions are another common pitfall. I once ordered 10,000 polypropylene lids for a container that was supposedly 'standard size.' The lids were 0.5 mm too small. They popped off during transport. That was a $1,200 mistake plus a customer complaint.

What to do:

I always ask for a 'production intent' sample—not a hand-made prototype, but one from the actual production tooling. The first article from the tool is where most dimensional issues show up.

Step 4: Verify Weight and Wall Thickness

This is one that catches people off guard. Plastic packaging is often priced by weight. A thinner wall saves money but might compromise strength. I've had orders where the supplier 'optimized' the weight to save us money, but the resulting container was too flimsy for our application.

What to do:

I don't have hard data on industry-wide weight variance rates, but based on our orders, I'd estimate about 10% of first-time orders have a weight deviation outside tolerance. Catching it early saves a lot of rework.

Step 5: Don't Assume 'Silicone' Is the Same as Plastic

One of the trickier questions that comes up: is silicone the same as plastic? The short answer is no. Silicone is a synthetic polymer, like plastic, but its chemistry is fundamentally different. Plastics (PET, PP, HDPE) are carbon-based polymers. Silicone is a silicon-oxygen backbone with organic side groups. This gives silicone different properties: it's more flexible, has higher heat resistance (up to 230°C for some grades), and is generally more expensive.

What to do:

This distinction matters because using the wrong material can lead to product failure, especially if the container needs to withstand hot filling or microwaving.

Step 6: Review Lead Times and Shipping Realities

Every spreadsheet analysis I've done has pointed to the cheapest supplier. But something always felt off about their communication. Turns out, that 'slow to reply' was a preview of 'slow to deliver.' After the third late delivery from a low-cost vendor, I created a buffer time rule: add 20% to the quoted lead time for new suppliers until they prove reliable.

What to do:

The most frustrating part of this process: even with written agreements, delays happen. I've found that building in a buffer of 2-3 weeks for first orders is prudent. You'd think 'two weeks' means two weeks, but in reality, it often means 'two weeks plus a few days for quality checks.' I wish I had tracked lead time variances more carefully from the start.

Step 7: Don't Try to Be a 'One-Stop Shop'

Here's a lesson I learned the hard way: trying to source everything from one supplier because they claim to be 'full service' is a recipe for disappointment. I once used a supplier who insisted they could handle both rigid plastic containers and flexible film pouches. The containers were fine. The pouches had sealing issues. I spent weeks troubleshooting with them before switching to a specialist.

What to do:

I'd rather work with a specialist who knows their limits than a generalist who overpromises. The vendor who said 'we're great at rigid plastics but not for pharmaceutical-grade packaging—here's a specialist' earned my loyalty for the rest of their portfolio.

Final Checklist (Download and Use)

  1. Material spec confirmed (resin type, grade, properties)
  2. Color approved on actual material (with Delta E tolerance)
  3. Dimensions verified (CAD, first article, physical fit test)
  4. Weight and wall thickness agreed (with tolerance and certificate)
  5. Material differentiation understood (plastic vs. silicone vs. other options)
  6. Lead time and shipping confirmed (with buffer included)
  7. Supplier specialization checked (not one-stop-shop illusion)

We've caught 47 potential errors using this checklist in the past 18 months. That's 47 orders that didn't go wrong because we checked before production. The cost of a mistake: anywhere from $400 for a small color reprint to $3,200 for a full order redo. That's roughly $15,000 in avoided losses annually.

If I could redo my first few years in packaging procurement, I'd invest in better specifications upfront. But given what I knew then—essentially nothing about the nuances of resin selection, color matching, and vendor communication—my mistakes were reasonable. Yours don't have to be.

Amcor Technical Desk

The desk prepares packaging, polymer, compliance, and sustainability notes for B2B teams comparing Amcor rigid plastics and related material programs.