Mylar is one of those materials buyers, engineers, and converters search for every day – usually as “Mylar film”, “Mylar roll” or “Mylar bag”. Yet many teams are not fully clear about what Mylar actually is, how its properties compare with other films, and how to choose the right specification for real projects.
In technical terms, “Mylar” is originally a registered brand name of biaxially oriented polyethylene terephthalate (BOPET) from DuPont, but in daily use it has become a generic term for BOPET polyester film. When people say “Mylar film”, they are usually talking about a clear or metallized PET film with high strength, good barrier and excellent thermal stability.
For packaging, Mylar sits at the center of many high-performance structures: from PET/PE snack pouches and coffee bags to PET/VMPET/PE high-barrier laminates and lidding films. For industrial markets, it appears in electrical insulation, labels, reflective insulation, solar backsheets and more.
Understanding the underlying material properties helps you design better packs, reduce risk on the packaging line, and speak the same language as your film supplier.
This guide looks at Mylar strictly from a practical, engineering-and-buyer perspective:
- What Mylar actually is, and how it relates to PET/BOPET
- Key mechanical, barrier, optical, thermal and electrical properties
- Typical packaging and industrial applications
- How to choose thickness, surface treatment and laminate structures
- What to prepare when you talk with a Mylar film manufacturer or supplier
If you also want market trends and application case studies, you can read CloudFilm’s dedicated article Mylar PET features and market insights as a companion to this more property-focused guide.
What Is Mylar Film?
In practical packaging and industrial projects, “Mylar”, “PET film”, “polyester film” and “BOPET film” are often used almost interchangeably. To design correctly, it helps to clarify a few key points:
- Material family – Mylar is a biaxially oriented polyester based on polyethylene terephthalate (PET). It belongs to the same family as other BOPET films but is often used as a shorthand name in the market.
- Orientation – The film is stretched in both machine direction (MD) and transverse direction (TD). This orientation process dramatically improves tensile strength, stiffness and dimensional stability compared with unoriented PET.
- Typical thickness range – For flexible packaging, common Mylar gauges are around 8–23 μm; for labels, insulation and technical laminates, thickness can go much higher, even above 100 μm in some industrial applications.
- Clear vs metallized vs coated – Clear Mylar provides strength, clarity and basic barrier; metallized (aluminized) Mylar adds very high oxygen, moisture and light barrier; coated Mylar adds heat-seal, primer or functional barrier layers.
In flexible packaging, the “Mylar bag” you see on the shelf is almost never a single-layer film. It is usually a laminate, for example:
- PET/PE or PET/CPP for snacks, powdered products or transparent windows
- PET/VMPET/PE or PET/AL/PE for coffee, tea and aroma-sensitive dry foods
- PET/PA/PE or PET/PA/CPP for pouches that need extra puncture resistance
CloudFilm’s BOPET portfolio covers gloss, matte, metallized and coated Mylar-type films, and can be supplied either as base PET film rolls or as part of PET/PE and other laminates for ready-to-convert packaging structures.
Key Physical And Barrier Properties Of Mylar
From an engineering standpoint, Mylar’s value comes from a balanced property profile rather than any single “magic number”. The most important groups of properties are:
2.1 Mechanical Strength And Dimensional Stability
- High tensile strength & modulus – Mylar’s biaxial orientation gives it high tensile strength and stiffness compared with films like PE and many PP grades. That means less stretching on high-speed lines and better pack appearance.
- Dimensional stability – Mylar keeps its size and shape across a wide temperature range, which is critical for tight registration in multi-color printing, lamination and die-cutting.
- Excellent creep resistance – Under constant load, Mylar deforms less than many other packaging films, which benefits long-term hanging displays, labels and industrial laminates.
2.2 Barrier Performance
On its own, clear Mylar offers good oxygen barrier and moderate moisture barrier, more than enough for many dry foods, powders, and non-food applications. When combined with metallization or oxide coatings, barrier performance improves dramatically:
- Metallized (aluminized) Mylar – A vacuum-deposited aluminum layer provides very high oxygen, moisture and light barrier, making aluminized Mylar a standard choice for coffee, instant beverages, nuts and pet food. CloudFilm’s aluminized PET film is a typical Mylar-type VMPET solution for such uses.
- ALOx or SiOx coated Mylar – Transparent high-barrier versions that combine good oxygen barrier with see-through appearance. These are increasingly used when brands want “window” designs without sacrificing shelf life.
2.3 Optical And Surface Properties
- High clarity and gloss – Clear Mylar gives excellent product visibility and sharp graphics, ideal for premium pouches and lidding films.
- Matte and soft-touch options – By adjusting surface treatment or coating, Mylar can provide matte, low-gloss or soft-touch effects that help brands create a more tactile, high-end look.
- Excellent printability – With corona or chemically treated surfaces, Mylar is highly suitable for gravure, flexo and digital printing. CloudFilm’s flexible packaging printing guide explains how to combine film, ink system and printing technology for consistent results across long runs. You can refer to the comprehensive guide to flexible packaging printing when you plan new designs.
2.4 Thermal And Electrical Properties
- Wide operating temperature – Mylar retains stiffness and strength at relatively high temperatures, which is why it is often used as the outer layer in retort pouches, lidding films and ovenable structures.
- Low thermal shrinkage – Controlled shrink characteristics help maintain pack shape and minimize distortion of printed graphics.
- Good dielectric strength – For motors, transformers, capacitors and cables, Mylar’s dielectric properties and heat resistance make it a standard insulation film in many industries.
2.5 Chemical Resistance And Durability
Mylar resists many oils, fats, and chemicals, and offers good abrasion resistance. For packaging, this means:
- Less risk of pinholes from handling and logistics
- Better print protection on the outside of pouches and lidding
- Stable properties during long-term storage or repeated flexing
Mylar In Flexible Packaging Applications
Because of its property balance, Mylar is one of the most universal “backbone films” in modern flexible packaging. Some of the most common Mylar-based applications include:
3.1 Snacks, Confectionery And Dry Foods
- Structures – PET/PE, PET/CPP, PET/VMPET/PE
- Formats – Pillow bags, stand-up pouches, quad-seal bags, flow-wrap film
- Why Mylar? – High stiffness and clarity on the outside, reliable sealing via PE or CPP on the inside, plus optional metallization for extended shelf life.
Many snack and candy projects start from a simple PET/PE or PET/VMPET/PE structure, then fine-tune thicknesses based on drop tests, shelf-life trials and cost per pack. The flexible food packaging types and trends guide gives a broader overview of how Mylar fits into different food segments.
3.2 Coffee, Tea And High-Aroma Products
- Typical structures – PET/AL/PE, PET/VMPET/PE, PET/ALOx PET/PE
- Key requirements – Very high oxygen and light barrier, aroma retention, puncture resistance and valve compatibility.
Here, Mylar provides a printable outer layer with excellent heat resistance, while the aluminum or metallized layer handles barrier duties. Sealant films such as PE or CPP manage hot-tack and machinability on coffee packaging lines.
3.3 Frozen Food, Meat And Seafood
Typical structures – PET/PA/PE, PET/PE, PET/PA/CPP
Why Mylar? – Mechanical strength and low-temperature toughness when combined with PA (nylon) and PE, plus good print quality for brand blocks on frozen shelves.
CloudFilm’s PET/PE laminated film is a classic Mylar-based solution for many frozen food and vacuum bag projects that require strong seals and shelf appeal at the same time.
3.4 Pharmaceutical, Medical And Personal Care
Mylar’s clean surface, dimensional stability and resistance to many chemicals make it a preferred outer layer for:
- Diagnostic pouches and reagent kits
- Medical device packaging
- Cosmetic, hair-care and personal-care pouches
In these segments, brand owners often combine Mylar with easy-tear or peelable sealant films to improve patient and consumer experience.
3.5 Relationship With Other Film Families
Mylar is rarely used alone. It usually works together with other film families:
- With BOPP for labels, overwraps and some lower-barrier packs – see CloudFilm’s BOPP film range for typical examples.
- With CPP as a high-temperature sealant layer for retort or hot-fill pouches.
- With BOPE / MDO-PE in new mono-PE recyclable structures where Mylar may be replaced or combined strategically to improve recyclability. For design inspiration, CloudFilm’s recyclable flexible packaging guide is a helpful reference.
Mylar For Industrial And Technical Uses
Beyond packaging, Mylar is a workhorse material in many industrial and technical applications:
4.1 Electrical Insulation
- Slot liners, phase insulation and wedges in motors
- Insulation layers in transformers and generators
- Dielectric film in some capacitor designs
- Wrapping and insulation for cables
Here, Mylar’s dielectric strength, thermal stability and dimensional control reduce the risk of partial discharge, tracking and premature failure.
4.2 Labels, Nameplates And Graphic Arts
High stiffness and excellent printability make Mylar a strong candidate for:
- Durable labels (e.g. appliance, automotive, industrial equipment)
- Nameplates and control-panel overlays
- High-precision graphic arts and overlay films
Compared with softer films, Mylar label stock keeps its shape better, resists edge-curling and maintains high print definition over time.
4.3 Reflective Insulation And Construction
Metallized Mylar is widely used in:
- Reflective insulation laminates for buildings and HVAC ducts
- Radiant barrier films behind radiators or under roofing
- Reflective layers in specialty tapes and industrial laminates
The combination of high reflectivity, low emissivity and mechanical robustness makes it stable in many construction environments.
4.4 Solar Backsheets And Energy Applications
PET-based Mylar films are a key component in many photovoltaic backsheets, providing mechanical support, electrical insulation and weathering resistance. CloudFilm supplies polyester films used in photovoltaic backsheet film
structures and can coordinate with converters to match the right grade to your module design.
How To Choose The Right Mylar Specification
When you work with a Mylar film manufacturer or supplier, you don’t need to know every technical detail, but you do need a clear checklist. A practical selection process usually looks like this:
5.1 Define Product And Pack Type
- What are you packing or insulating? (food, coffee, pet food, chemical, electronic parts, motor, cable, etc.)
- What is the pack format? (pouch, lidding, flow-wrap, label, tape, laminate sheet…)
- What is the expected shelf life or service life?
The answers will quickly narrow down whether you need clear, metallized, high-barrier coated or specialty Mylar.
5.2 Choose Clear Vs Metallized Vs High-Barrier
- Clear Mylar – For applications that need transparency and only medium barrier, such as many dry foods, labels and some industrial wraps.
- Metallized (VMPET) Mylar – For high-aroma, oxygen-sensitive or light-sensitive products such as coffee, nuts and pet food.
- High-barrier coated Mylar – For transparent packs that still need strong oxygen barrier; often used in premium food and healthcare packaging.
CloudFilm’s metallized films portfolio covers metallized BOPP, PET, CPP and CPE, allowing you to choose the most cost-effective barrier substrate for each project.
5.3 Select Thickness And Mechanical Strength
- For typical flexible packaging, PET thickness of 8–23 μm is common.
- For heavier pouches, industrial laminates or labels, thicker gauges may be needed.
- Thicker Mylar improves stiffness and puncture resistance but also increases cost and roll weight.
If you are comparing PET-based Mylar vs CPP structures, CloudFilm’s PET vs CPP film comparison
is a useful visual reference on stiffness, sealability and cost.
5.4 Consider Surface Treatment And Finish
- Corona-treated vs chemically coated surface for better ink adhesion
- Gloss, matte or soft-touch aesthetic
- Easy-tear or easy-peel functionality through special structures or coatings
5.5 Map Process Conditions And Regulations
- Process – Form-fill-seal, vacuum, retort, hot-fill, ovenable, heat-seal range, line speed
- Regulatory – Food contact regulations (FDA, EU, etc.), pharma or medical standards where applicable
- End-of-life – Recyclability targets and local recycling infrastructure
For teams systematically comparing Mylar and other film families (PE, BOPP, PA etc.), CloudFilm’s guide to plastic film types
helps you build a clear overview of each material’s strengths and limits.
Working With A Mylar Film Manufacturer And Supplier
Choosing the right material is only half the job; choosing the right partner is equally important. CloudFilm CloudFilm is a flexible packaging film manufacturer and exporter based in China, supplying Mylar-type BOPET, BOPP, BOPA, CPP, PE and high-barrier films to customers worldwide.
A good Mylar film manufacturer and supplier should be able to:
- Provide consistent film quality (thickness profile, COF, shrinkage, optical properties) backed by QC data
- Offer application-driven recommendations, not just a price list
- Support trial rolls, lab testing and scale-up to container volumes
- Help with documentation: food-contact declarations, technical data sheets, MSDS where applicable
- Coordinate export logistics, pallets, packing and lead times suitable for your region
6.1 What To Tell Your Supplier
When you send an inquiry to a Mylar film supplier, including the following information will speed up engineering and quotation:
- Product & application – e.g. “drip coffee bags, 12-month shelf life” or “motor slot liner, class F insulation”
- Pack or laminate structure – current structure if any (PET/AL/PE, PET/PE, PET/PA/PE…)
- Target thickness & width – or at least a ballpark range
- Process & machine type – FFS, pouch machine, laminator, printing method, typical line speed
- Regulatory requirements – e.g. EU food-contact, US FDA, pharma, RoHS/REACH, etc.
- Estimated volume – trial quantity and target monthly/annual demand
CloudFilm’s products overview
page shows typical film families and flexible pouches that can be combined with Mylar for full packaging solutions, from roll stock to ready-made bags.
FAQs: Mylar Properties, Uses And Buying Tips
Q1. Is Mylar The Same As PET?
Strictly speaking, Mylar is a brand name originally used for biaxially oriented PET films. In everyday usage, people often use “Mylar”, “PET film” and “BOPET film” to describe very similar polyester films. For packaging and industrial design, it’s usually safe to treat “Mylar film” as a high-quality BOPET polyester film.
Q2. What Thickness Of Mylar Is Common In Packaging?
- 8–12 μm: overwraps, twist films, some labels
- 12–23 μm: most laminated pouches, lidding and general flexible packaging
- 23 μm: heavy-duty pouches, labels, insulation and industrial laminates
Your supplier can help you balance stiffness, puncture resistance and cost per pack based on pack size, filling method and shelf-life goals.
Q3. Is Mylar Food-Safe?
Yes, PET-based Mylar films are widely used as food-contact materials when they comply with relevant regional regulations (such as EU or FDA). In most flexible packaging, Mylar is the outer structural and printing layer, while inner sealant layers like PE or CPP handle direct food contact and heat sealing. Always confirm regulatory status of the final laminate with your supplier.
Q4. How Does Mylar Compare With Aluminum Foil?
- Barrier – Aluminum foil provides near-absolute barrier to oxygen and moisture; metallized Mylar offers very high but slightly lower barrier.
- Flex-crack resistance – Mylar laminates usually resist flex-cracking better than pure foil structures.
- Weight and cost – Metallized Mylar can reduce weight compared with foil, with a different cost structure depending on specification.
- Recyclability – Both foil and metallized structures are more complex to recycle than simple mono-material films; design must consider local recycling streams.
Q5. Can Mylar Be Used In Retort Or Ovenable Packaging?
Yes. Mylar’s thermal stability makes it suitable as an outer layer in many retort and ovenable structures, especially when combined with CPP or special PE sealant layers. However, not every PET or Mylar grade is designed for high-temperature steam or oven use, so always specify your process conditions (retort temperature/time, oven temperature, microwave vs conventional) when discussing with your supplier.
Q6. Is Mylar Recyclable?
Mylar is made from PET, which is a recyclable polymer. In practice, recyclability depends more on the laminate structure (e.g. PET/PE, PET/AL/PE) and local recycling systems than on the Mylar itself.
If recyclability is a key driver, discuss mono-material or PE-rich structures with your supplier. CloudFilm’s recyclable flexible packaging guide shows several ways to move from traditional laminates toward more recyclable solutions.
Q7. How Is Mylar Different From BOPP?
- Mylar (PET) generally has higher stiffness, better dimensional stability and higher temperature resistance than BOPP.
- BOPP often offers excellent moisture barrier at lower cost and is widely used as an inner or middle layer.
- Mylar is preferred when print registration, heat resistance or mechanical strength are critical; BOPP is attractive where cost and moisture barrier dominate.
Q8. How Do I Calculate Mylar Roll Weight Or Yield?
To estimate roll weight, you need density (around 1.3–1.4 g/cm³ for polyester), thickness and total area. Many buyers prefer to discuss in terms of “square meters per kilogram” or “pouches per kilogram of laminate”. CloudFilm’s team can help you run these calculations based on your real bag sizes, scrap rates and roll widths.
Q9. Can CloudFilm Supply Both Mylar Film And Finished Pouches?
Yes. CloudFilm is not only a Mylar film manufacturer and exporter, but also a flexible packaging solution provider. Besides Mylar-type PET films, CloudFilm can supply:
- BOPP, BOPA, CPP, PE and high-barrier films
- PET/PE and other laminates ready for FFS lines
- A wide range of flexible pouches for coffee, rice, snacks, pet food, pharma and more
Depending on your internal converting capabilities, you can source only Mylar films, complete laminates, or ready-made pouches from CloudFilm and its converting partners.
