PETG vs Polycarbonate vs Acrylic Boxes: Material Guide

PETG vs Polycarbonate vs Acrylic: The 30-Second Answer

The petg vs polycarbonate question — with cast acrylic as the third contender — decides more custom clear-box specs than any other choice. For a custom B2B clear box, pick cast acrylic when clarity, edge finish, and UV stability drive the spec — display boxes, retail fixtures, signage enclosures, premium presentation cases. Pick polycarbonate when the box gets dropped, hit, or pressed against — tool cases, shipping enclosures, machine-side covers, vandal-resistant signage. Pick PETG when the design is thermoformed, the wall is under 3mm, and budget matters more than premium finish — clamshell packaging, light-duty point-of-sale boxes, low-cost protective covers.

In our production experience quoting clear-box jobs across all three materials, the mistake we see most often is buyers spec’ing polycarbonate because they read it’s “stronger” and stopping there — then receiving boxes with an amber tint that yellows visibly within a couple of years, paying a real premium, and finding their fabricator can’t deliver clean laser-cut edges anyway. The opposite mistake is spec’ing cast acrylic for a box tossed into warehouse bins daily, then dealing with replacement orders when corners crack. This guide walks through the material data — impact, scratch, UV, and cost, drawn from published standards and producer datasheets — and tells you which material wins each round. It is the pair-by-pair scorecard; for the acrylic-anchored argument — why we build display work in cast acrylic specifically — see why cast acrylic beats PETG and polycarbonate.

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How the Three Materials Score Across Six Dimensions

Before diving into each dimension, here’s the headline scorecard, drawn from published material data (ASTM/ISO test methods, producer datasheets, and materials databases) plus our own fabrication and cost experience. We score on a 1–5 scale per dimension where 5 is best in class.

Material comparison scorecard — acrylic vs polycarbonate vs PETG

Dimension	Cast Acrylic	Polycarbonate	PETG	Winner
Optical clarity (light transmission, edge clarity)	5/5 (~92%, crystal edge)	3/5 (~88%, amber tint)	4/5 (~90%, faint blue)	Acrylic
Impact strength (Izod notched, ASTM D256)	2/5 (~0.3–0.5 ft-lb/in)	5/5 (~12–18 ft-lb/in)	4/5 (~1.5–2 ft-lb/in)	Polycarbonate
Scratch resistance (surface hardness)	4/5 (hardest surface)	3/5 (soft, needs coating)	2/5 (softest, scuffs)	Acrylic
UV stability (outdoor color hold)	5/5 (best, ~decade)	2/5 (yellows untreated)	3/5 (intermediate)	Acrylic
Cost (per finished box, B2B 50-piece MOQ)	4/5 ($18–$32)	2/5 ($26–$45)	5/5 ($11–$18)	PETG
Recyclability (2026 municipal access)	2/5 (resin 7, specialty)	1/5 (resin 7, rare)	5/5 (resin 1, curbside)	PETG

The verdict per material: cast acrylic wins on clarity, scratch, UV, and overall finish quality — the right default for any visible-edge custom acrylic plastic box. Polycarbonate wins on impact alone but pays for it in clarity, UV stability, and cost. PETG splits the difference and dominates only on cost and recyclability, making it the right call when the box is disposable or single-use.

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Optical Clarity — Where Acrylic Genuinely Pulls Ahead

The clarity gap between the three materials is the most visually obvious property when you put them side by side, and it’s the one buyers underweight most often when they spec a custom clear box. Cast acrylic transmits roughly 92% of visible light per ASTM D1003 testing, with no detectable tint at any thickness our customers typically order (3–20mm). PETG transmits about 90% with a faint blue tint that becomes visible on walls thicker than 5mm and along thicker laser-routed edges. Polycarbonate transmits around 88% with a noticeable amber tint that deepens with thickness and gets worse over time as UV exposure accumulates.

For a side-by-side acrylic plastic box versus polycarbonate box on a retail shelf, the clarity difference is the first thing a customer notices — even if they can’t articulate why. The amber tint on polycarbonate reads as “older” or “lower quality” instinctively, even when the polycarbonate box is brand new and identical in every other dimension. PETG sits in the middle: cleaner than polycarbonate, slightly less crisp than acrylic, and acceptable for most secondary display applications where the box isn’t the hero.

Edge clarity is the second axis where the materials separate. Cast acrylic, when laser-cut, produces a flame-polished glass-like edge straight off our CO2 laser line — no secondary polishing required, and the optical clarity at the edge matches the face. Polycarbonate cannot be laser-cut cleanly; the material chars and melts, releasing chlorine-like fumes that damage equipment, so we route it on CNC and finish each edge mechanically through 4–6 grit progressions. The mechanically polished PC edge is acceptable but never matches a laser-cut acrylic edge. PETG sits in between — also CNC-routed, also mechanically finished, with marginally cleaner edges than polycarbonate but still well below cast acrylic’s laser finish.

For any project where the box is the display vehicle — premium retail packaging, presentation cases, signage enclosures, automotive showroom countertop displays — acrylic wins on clarity alone. The two-way polycarbonate vs acrylic comparison without PETG follows a similar pattern: polycarbonate’s higher impact resistance is the only factor that overrides acrylic’s clarity advantage.

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Impact Strength — Why Polycarbonate Survives the Drop

Impact is the only dimension where polycarbonate clearly beats both acrylic and PETG, and it’s the dimension that flips the recommendation when the application demands it. The mechanism is simple: under a sharp corner impact, cast acrylic is glassy and brittle — it stores energy elastically until a crack initiates, then that crack runs and the corner shatters. Polycarbonate is ductile — it yields and deforms, absorbing the impact energy plastically instead of releasing it as a crack. PETG sits in between, tougher than acrylic but well short of polycarbonate. Corners are the failure point on any rectangular enclosure because they concentrate stress; a flat-face drop is far more forgiving and rarely separates the materials.

The published notched-impact numbers make the ranking concrete. Per ASTM D256¹ — the standard Izod test for notched-impact resistance of plastics — typical values run:

• Polycarbonate: ~12–18 ft-lb/in of notch — the toughest of the three by a wide margin.
• PETG: ~1.5–2 ft-lb/in — several times tougher than acrylic, though far below PC.
• Cast acrylic: ~0.3–0.5 ft-lb/in — the brittle baseline; a small notch or scratch dramatically lowers where it fractures.

That puts polycarbonate on the order of 20–40 times acrylic’s notched-impact resistance. Flexural behavior (ASTM D790²) tells the same story from the other side: polycarbonate bends past its yield point before it breaks, while acrylic snaps clean with little warning.

The practical takeaway: if your box gets dropped, stacked aggressively, or shipped without protective packaging, spec polycarbonate. If it sits on a counter or behind a window, acrylic’s impact strength is more than the application demands. For the in-between case where some shatter resistance matters but clarity still drives the spec, PETG is the third option worth pricing. In our own shop we do a simple in-house drop-check on a loaded sample case before a box ships — a sanity check on the bonded corners, not a lab test — and brittle-corner cracking on thin acrylic is a failure mode we design around rather than discover in the field.

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UV + Yellowing — Outdoor Weathering Behavior

UV resistance separates acrylic from polycarbonate even more sharply than impact resistance does, but in the opposite direction — and here the chemistry is the whole story. Polycarbonate’s carbonate linkages absorb UV in the 300–340nm band, which breaks polymer chains at the surface and generates yellow degradation products; that’s why untreated PC visibly yellows and surface-embrittles (often with fine chalking) within roughly 1–2 years of direct sun. Cast acrylic’s methyl-methacrylate backbone is largely transparent at those wavelengths, so the surface stays clear — producer weathering literature and accelerated-weathering programs (ASTM G154 / G155, and Q-Lab QUV fluorescent-UV testing) consistently show cast acrylic keeping essentially its as-new appearance over a decade outdoors. PETG sits in between: more UV-stable than untreated PC, less than acrylic.

The ranking, from most stable to least:

• Cast acrylic (no UV stabilizer): best-in-class color hold; producer datasheets (e.g. Röhm PLEXIGLAS) cite roughly a decade of outdoor service with negligible yellowing.
• PETG: intermediate — noticeably better than untreated PC but not a true outdoor-signage material.
• Polycarbonate (no UV stabilizer): the worst — clearly yellowed and surface-brittle within 1–2 years of direct exposure.
• UV-stabilized polycarbonate (e.g. Covestro Makrolon UV grades): substantially better than untreated PC via a co-extruded UV-absorbing cap layer, but still short of acrylic and at a material-cost premium.

The UV gap matters most for outdoor signage boxes, storefront display enclosures, and any box sitting within a few meters of a south-facing window. Untreated polycarbonate will look noticeably worse within a couple of years and need replacement before the typical refresh cycle, while untreated cast acrylic holds its appearance for years in the same conditions.

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Cost — $/kg Material vs $/Part Finished

Material cost per kg only tells part of the cost story for any custom acrylic plastic box — fabrication labor and finishing time often matter more for the finished unit price. Here’s the breakdown across both axes, using indicative US distributor pricing as of June 2025 (your local market may vary 15–25%).

Raw material cost per kg (June 2025, US distributor)

• PETG sheet: ~$2.80/kg ($1.27/lb). Cheapest of the three.
• Cast acrylic sheet: ~$4.20/kg ($1.91/lb). Roughly 50% more than PETG.
• Polycarbonate sheet: ~$5.50/kg ($2.50/lb). Roughly twice PETG and 30% more than cast acrylic.
• UV-stabilized polycarbonate: ~$6.50/kg ($2.95/lb). Roughly 15–25% premium over standard PC.

Finished box cost per unit (50-piece MOQ, 250×150×150mm, B2B custom)

• PETG (3mm thermoformed): $11–$18 per box. Cheapest finished cost. Limited finishes, no laser-cut edges.
• Cast acrylic (5–6mm laser-cut + solvent-bonded): $18–$32 per box. Premium finish, fastest fabrication, widest finish options.
• Polycarbonate (6mm CNC-routed + adhesive-bonded): $26–$45 per box. Highest finished cost, longest lead time, most complex polishing.

The cost rank flips between raw material and finished part because fabrication labor compounds the differences. Cast acrylic laser-cuts in minutes with a finished edge straight off the machine; polycarbonate takes 3–5 times longer on CNC plus mechanical polishing. PETG thermoforms cleanly for simple shapes, which is why it dominates on cost when the design is thermoformable, but becomes uncompetitive against acrylic when the design needs flat panels with bonded corners — which describes most premium display boxes.

Scrap rate is the cost factor most buyers miss. In our production experience cast acrylic and PETG run cleanly, while polycarbonate’s moisture sensitivity during thermoforming and its tendency to scratch on handling push scrap meaningfully higher on complex shapes — and that waste flows directly into the finished part price.

For an exact quote on your specific box dimensions, wall thickness, finish, and quantity, send specs to inquiry@wetopacrylic.com — we’ll quote all three materials when the application genuinely calls for comparison and tell you directly which we recommend for your use case. We respond within 24 hours.

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Recyclability — What Each Material Can Claim in 2026

Sustainability claims have become a real RFQ requirement in 2026, especially for B2B buyers selling into European and California markets where extended producer responsibility (EPR) regulations are tightening. Here’s what each material can honestly claim under 2026 municipal recycling realities, referenced against the SPI Resin Identification Codes³.

PETG (resin code 1, sometimes 7 by region): the most municipally recyclable of the three. PETG is chemically compatible with the PET stream that handles beverage bottles, though some facilities sort it as “other” due to the glycol modifier. In practice, PETG packaging is accepted by 30–50% of US curbside programs and higher in EU EPR markets.⁴

Cast acrylic (resin code 7, “other”): technically recyclable but rarely accepted curbside. Specialty channels exist — chemical depolymerization back to MMA monomer, mechanical regrinding for non-clear use — but municipal programs almost never accept it. The honest claim is “recyclable through specialty channels.” We can take back our own production scrap for regrind into colored acrylic, which is an option some buyers like for closed-loop programs.

Polycarbonate (resin code 7, “other”): the hardest to recycle. PC’s complex polymer structure makes mechanical recycling impractical, and chemical pathways exist at industrial scale but are not municipally accessible. PC boxes end up in landfill or incineration in most markets.

Practical guidance for 2026 RFQs: if recycle-claim is a hard requirement, default to PETG for disposable boxes and cast acrylic with a closed-loop takeback for premium display boxes. Polycarbonate is the right call only when impact, heat, or security override the sustainability cost.

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Which Material to Spec for Your Box

For the vast majority of custom B2B clear-box projects, the right answer is cast acrylic — specifically a laser-cut, solvent-bonded acrylic plastic box at 4–6mm wall thickness depending on the application. The decision tree below covers the cases where polycarbonate or PETG is the correct call instead.

Spec cast acrylic if: the box is a display vehicle where clarity drives buyer perception (retail display, signage enclosure, premium presentation case, point-of-sale fixture), OR the box sits outdoors or near a window where UV stability matters, OR the design needs invisible solvent-bonded corners, OR the design includes laser-cut details, custom shapes, or polished edges, OR the buyer values long-term color stability over impact survival.

Spec polycarbonate if: the box gets dropped, handled aggressively, stacked without packaging, or used as a tool case or shipping enclosure, OR ballistic / vandal resistance is part of the spec, OR the box sits within 30cm of a heat source above 95°C, OR the design tolerates the amber tint and faster yellowing in exchange for impact survival.

Spec PETG if: the design is thermoformed (clamshell, vacuum-formed enclosure, compound curve), OR the wall thickness is under 3mm where acrylic gets fragile, OR the buyer needs a curbside-recyclable claim, OR budget pressure dominates and the box is single-use or short-lifecycle, OR the application falls between acrylic and polycarbonate on impact requirements.

For premium custom display boxes, presentation cases, and retail fixtures, we fabricate primarily in cast acrylic — see our custom acrylic boxes hub for the box formats and our acrylic display cases hub for the full product range and configuration options. If your design brief specifies polycarbonate or PETG and you’d like a second opinion on whether cast acrylic is viable, include that question when you send your RFQ. I review every quote personally and will give you a direct answer — if polycarbonate or PETG is genuinely the right material for your application, I’ll confirm that and we’ll source it; if cast acrylic will meet the requirement at lower cost or better finish, I’ll tell you that too.

For broader sourcing process help, our custom acrylic RFQ guide walks through every spec you should include upfront to get accurate quotes the first time. To start your quote now, send your specs through our contact form and we’ll respond within 24 hours.

Related guides

• Acrylic Sneeze Guard Specs 2026 — Healthcare & Restaurant Buyer Guide
• Laser Etched Acrylic Logo Trays — A Brand Buyer’s Spec Sheet

Footnotes

1. Izod notched-impact values (ASTM D256) compared across the three materials, from producer datasheets and materials databases: cast acrylic (~0.3–0.5 ft-lb/in) per Plaskolite OPTIX and Röhm PLEXIGLAS datasheets; PETG (~1.5–2 ft-lb/in) per Eastman datasheets; polycarbonate (~12–18 ft-lb/in) per Covestro Makrolon / SABIC Lexan datasheets. Cross-referenced against the MakeItFrom and MatWeb material property databases. Values are published/typical ranges, not a single measurement. ↩

2. Flexural behavior per ASTM D790, illustrating polycarbonate’s ductile bend-before-break versus cast acrylic’s brittle clean fracture. General PMMA and polycarbonate mechanical property data via AZoM and the MatWeb materials database. ↩

3. SPI Resin Identification Codes (ASTM D7611) — the standardized resin coding system used to determine 2026 municipal recyclability for PETG (code 1), cast acrylic (code 7), and polycarbonate (code 7). ↩

4. U.S. Environmental Protection Agency. Plastics: Material-Specific Data — Facts and Figures about Materials, Waste and Recycling. https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/plastics-material-specific-data — EPA municipal recycling acceptance data for PET/PETG, polycarbonate, and acrylic resin streams cited in the recyclability comparison. ↩