APET vs PETG vs RPET: What's the Real Difference?
All three are PET. They are not interchangeable.
May 8, 2026 · K&R Plastics Substrate Team · 7 min read
All three substrates are PET — polyethylene terephthalate. They look similar on a shelf, ship under similar product names, and run through similar conversion processes. They are not interchangeable. Substrate buyers who treat them as the same thing eventually run into a job where the wrong PET fails — usually in a deep-draw form, a high-impact application, or a sustainability spec that requires recycled content.
This guide explains what makes APET, PETG, and RPET different at the polymer level, where each one wins in real applications, and how to pick the right grade for the job.
A quick PET chemistry primer
PET is a thermoplastic polyester, formed by reacting terephthalic acid with ethylene glycol. The result is a long-chain polymer that's strong, clear, dimensionally stable, and recyclable. It's the most common plastic in beverage bottles and one of the most common in packaging film and sheet.
The form PET takes depends on how it's processed:
Crystalline PET (CPET) has tightly aligned polymer chains, formed by slow cooling. It's opaque, mechanically tough, and used in dual-ovenable food trays. Not what we're talking about here.
Amorphous PET (APET) is rapidly cooled from the melt so the polymer chains stay disordered. The result is a clear, glassy substrate with good optical properties and moderate impact resistance. This is the "default" PET for clear packaging.
Glycol-modified PET (PETG) has its molecular structure tweaked by substituting a small fraction of the ethylene glycol with cyclohexanedimethanol (CHDM). The CHDM bulks up the polymer chain and prevents crystallization, which gives PETG a wider processing window, better impact, and improved clarity over APET.
Recycled PET (RPET) is APET (or sometimes PETG) made with post-consumer recycled content — usually from collected beverage bottles. The chemistry is the same as virgin PET, but the supply chain is different and the substrate carries a sustainability story.
The names get used loosely. Distributors and converters sometimes lump APET and PETG together, or use "PET" as a catch-all. For most applications it doesn't matter. For some, it matters a lot.
APET: the budget clear PET
APET is the standard clear PET for cost-driven packaging. It runs cheaper than PETG, prints cleanly, and forms predictably in shallow-to-moderate draws.
Strengths:
- Lowest-cost clear PET option
- Excellent optical clarity (slightly behind PETG)
- Compatible with all major print processes (toner, indigo, inkjet, screen, offset, litho)
- Recyclable in standard PET streams (#1)
- FDA-compliant grades available for direct food contact
- Stable, predictable processing
Weaknesses:
- Narrower thermoforming window than PETG
- Lower practical draw ratio (about 2:1 maximum)
- Stress-whitens at corners under aggressive draws
- Lower impact resistance than PETG
- Not as scratch-resistant as PETG
Where APET wins:
- Clear thermoformed packaging (trays, clamshells, blister packs)
- Clear lids on pre-printed cartons
- Retail packaging where clarity matters and impact doesn't
- Visual-merchandising packaging
- Print-and-form applications where the form is shallow
- Cost-driven food packaging
Typical gauge range: .010"–.080"
PETG: the upgraded clear PET
PETG is the premium clear PET. The glycol modification widens the processing window, improves impact, and produces parts that don't stress-whiten or haze under aggressive forming.
Strengths:
- Wider thermoforming window — more forgiving of operator variation
- Higher practical draw ratio (3:1 with technique)
- No stress whitening at corners
- Higher impact resistance than APET
- Excellent clarity (the clearest of the three)
- Compatible with all major print processes without surface treatment
- Easy to fabricate (drills, cuts, routs without cracking)
- FDA-compliant grades available
- Strong scratch resistance
Weaknesses:
- 30–60% more expensive than APET
- Lower service temperature than polycarbonate
- Can be attacked by aggressive solvent inks at the print line
Where PETG wins:
- Premium retail displays and store fixtures
- Sneeze guards and partitions
- Faceshields (economy alternative to polycarbonate)
- Machine guards
- Deep-draw thermoformed packaging (blister packs with aggressive draws, deep clamshells)
- Medical device packaging
- Brochure racks and card displays
- Any application where you need clarity AND impact
Typical gauge range: .015"–.250"
PETG page → · Download datasheet ↓
RPET: the sustainable PET
RPET is PET — typically APET-grade — made with post-consumer recycled content. The chemistry is identical to virgin PET (it's the same polymer), but the supply chain matters: bottles are collected, washed, decontaminated, repelletized, and re-extruded into sheet.
The sustainability story is real:
- Diverts waste from landfill
- Reduces virgin petroleum demand
- Lowers carbon footprint vs virgin PET
- Supports circular economy programs
- Often required by retailer sustainability commitments
The trade-offs are also real:
- Slightly higher haze than virgin APET (cosmetic, usually acceptable)
- Limited supply availability — recycled content is constrained by bottle collection rates
- Cost premium over virgin APET (usually 10–25%)
- Color consistency varies more across batches
- Some grades have particle inclusions visible under bright light (acceptable for most packaging)
Where RPET wins:
- Brand sustainability programs requiring post-consumer recycled content
- Retail packaging for sustainability-focused retailers
- Produce containers and food packaging where recyclability matters to the consumer
- Replacement substrate for virgin APET in cost-comparable applications
- Compliance programs (some jurisdictions require minimum recycled content)
Typical gauge range: .010"–.080" (similar to APET)
APET / RPET page → · Download datasheet ↓
Side-by-side comparison
| Property | APET | PETG | RPET |
|---|---|---|---|
| Polymer | Amorphous PET | Glycol-modified PET | Recycled PET (typically APET-grade) |
| Specific gravity | 1.34 | 1.27 | 1.34 |
| Tensile strength | 8,500 psi | 7,700 psi | 8,000–8,500 psi |
| Thermoforming window | Narrow | Wide | Narrow (similar to APET) |
| Practical draw ratio max | 2:1 | 3:1 | 2:1 |
| Stress whitening on corners | Possible | Minimal | Possible |
| Impact resistance | Moderate | High | Moderate |
| Optical clarity | Excellent | Best of the three | Slightly hazier than APET |
| FDA-compliant grades | Yes | Yes | Yes |
| Recycled content | None (virgin) | None (virgin) | Post-consumer (varies, often 30–100%) |
| Cost index | 1.0× | 1.4–1.6× | 1.1–1.25× |
| Recyclable | Yes (#1) | Yes (#1) | Yes (#1) |
Cost index is approximate and varies by gauge, supplier, and volume.
How to pick
Use this decision tree:
Q: Do you need post-consumer recycled content for a sustainability program?
- Yes → RPET (verify percent recycled content meets your spec)
- No → continue
Q: Is the part deep-drawn (over 2:1) or impact-rated?
- Yes → PETG
- No → continue
Q: Is cost the primary driver, with no clarity or impact constraints beyond standard packaging?
- Yes → APET
- No → PETG (it's only 30–60% more and gives you forming margin and impact headroom)
A simpler heuristic: if you're not sure and clarity matters, default to PETG. The cost premium is worth the forgiveness on press, on the forming line, and in the field.
Print compatibility — all three
All three PET variants run on every digital and conventional print process:
| Print method | APET | PETG | RPET |
|---|---|---|---|
| Toner / laser | ✓ | ✓ | ✓ |
| HP Indigo | ✓ | ✓ | ✓ |
| UV inkjet | ✓ | ✓ | ✓ |
| Solvent / eco-solvent inkjet | ✓ | ✓ (test for solvent attack) | ✓ |
| Screen | ✓ | ✓ | ✓ |
| Offset | ✓ | ✓ | ✓ |
| Litho | ✓ | ✓ | ✓ |
PETG and APET both print without surface treatment in most cases. RPET behaves identically to APET on press. The slight haze in some RPET grades shows under high-density solid colors but is rarely a problem in graphics-heavy print.
Common mistakes
Treating APET and PETG as interchangeable. They aren't. A part designed for APET that gets a deep-draw form will fail. A part specced as PETG that gets quoted as APET to save cost may stress-whiten or crack at corners. When the spec calls for a specific PET grade, source the specific grade.
Buying RPET without verifying recycled content percentage. "Recycled content" can mean anywhere from 5% to 100%. If your sustainability spec requires a specific percentage, verify the supplier's documentation. Without verification, you're trusting marketing language.
Defaulting to PETG when APET would do. The flip side of the first mistake. If the part is shallow-drawn, doesn't need impact, and is cost-sensitive, APET is the right substrate and PETG is a margin you don't need to spend.
Ignoring the haze difference on RPET in clarity-critical applications. RPET has slightly higher haze than virgin APET. For most packaging this is irrelevant. For high-end retail packaging where the consumer is comparing your clear lid to a competitor's, run a side-by-side before committing.
Not requesting sample sheets before specifying for a production run. Visual differences between APET, PETG, and RPET are subtle. Forming differences are not. Get sample sheets, run them through your forming line, and pick from data — not from a datasheet.
When to step outside PET entirely
PET (in any form) isn't always the right answer. Consider stepping outside the PET family when:
- Service temperature exceeds 160°F continuous — switch to polycarbonate or ABS
- Maximum impact resistance required — switch to polycarbonate
- Chemical resistance to aggressive solvents — switch to polypropylene or HDPE
- Cost is the only driver and clarity doesn't matter — switch to HIPS
- Live-hinge fatigue performance required — switch to polypropylene
- High-temperature dual-ovenable application — switch to CPET (crystalline PET)
For applications that genuinely need a PET — clarity, recyclability, food-contact, FDA compliance, ease of forming — APET, PETG, or RPET cover almost every use case.
Need help picking between APET, PETG, and RPET? Request samples of all three in your target gauge to compare on your forming line and your press. Or talk to a substrate specialist — we stock all three families and can help match the substrate to your application, your sustainability spec, and your cost target.