Feel U · Cannabis Packaging Guide · October 2026
The 3.5g Mylar bag — also commonly called a 3.5 gram Mylar bag or an eighth Mylar bag — is the workhorse of American cannabis retail. It holds an eighth of an ounce of flower, the single most common purchase size at dispensaries across the United States. But what exactly goes inside, how much room is left, and what makes this little pouch so essential to your brand? Let’s open one up and find out.
The Eighth: Why 3.5 Grams?
An eighth, short for one-eighth of an ounce, equals exactly 3.5 grams. For additional background on ounce-to-gram measurements and SI units, see the NIST SI guidance. It has been the default retail unit for cannabis flower in the United States since the earliest days of legal dispensary sales, and it remains the volume that the vast majority of American cannabis brands structure their product lines around. When a dispensary customer picks up a jar or bag of flower, chances are it is an eighth.
That makes the 3.5g Mylar bag the most produced, most purchased, and most handled cannabis package on the market. Brands order them by the tens of thousands. Dispensaries stock them on every shelf. And regulators in states with legal cannabis programs have built their packaging compliance frameworks around this exact format.
3.5g — One-eighth of an ounce, the standard cannabis retail unit.
What Actually Fits Inside
The short answer: about 3.5 grams of dried cannabis flower, comfortably. But the real answer depends on what you are packing and how dense it is. Here is a practical breakdown of what a standard 3.5g Mylar bag holds:
| Product Type | Typical Amount | Fits Comfortably? |
|---|---|---|
| Cannabis flower (dense buds) | 3.5 g (one eighth) | Yes — the bag is sized for this |
| Cannabis flower (fluffy buds) | 3.5 g | Yes — may fill more volume |
| Pre-rolled joints (1g each) | 2–3 joints | Yes — with room to spare |
| Gummies / edibles | 5–10 pieces | Yes — depending on piece size |
| Concentrates (wax / shatter) | 1–2 g | Yes — bag is larger than needed |
| Shake / small trim | 3.5 g | Yes — fills less volume than whole buds |
Table: Practical capacity of a standard 3.5g Mylar bag by product type
Flower density is the biggest variable. A dense, tightly trimmed indica nugget packs into a smaller footprint than a fluffy sativa bud of the same weight. A 3.5g bag designed for flower typically measures roughly 3 by 5 inches (about 7.6 by 12.7 cm), which gives enough interior space for a full eighth without crushing the buds or forcing the zipper seal under pressure.
Beyond Flower: Other Products That Work
While flower is the primary contents, many brands use 3.5g Mylar bags for other cannabis products. Pre-rolled joints, especially 1-gram cones, fit neatly — two or three lay flat inside with the zipper sealing above them. Edible brands use them for gummy multi-packs and chocolate pieces. Concentrate producers sometimes use them for wax or shatter, though smaller 1g or 2g pouches are more common for extracts. For a broader overview of what Mylar bags are used for, different applications can require different dimensions and structures.
The versatility comes from the bag’s barrier film construction. The same multi-layer laminate that protects flower from oxygen and moisture also preserves the freshness of edibles and prevents terpene loss in concentrates. This is why many American cannabis operators standardize on the 3.5g format across multiple product lines — one bag size, multiple SKUs.
The Barrier: How Mylar Protects Your Product
A 3.5g cannabis Mylar bag is not just a simple plastic pouch. It is a precision-engineered multi-layer barrier structure, typically built from three or more laminated films:
1. Outer Print Layer
PET (polyester) film that carries your brand’s custom-printed artwork, available in matte, glossy, holographic, and soft-touch finishes.
2. Metalized Barrier
A thin layer of aluminum foil or VMPET (metalized polyester) that blocks oxygen, moisture, and UV light — the three things that degrade cannabis potency and flavor.
3. Inner Seal Layer
PE (polyethylene) or LLDPE food-grade film that enables clean heat-sealing and provides a food-safe contact surface for the product inside.
4. Zipper Closure
A resealable track zipper that lets consumers open and reclose the bag, preserving freshness between uses.
The total film thickness for cannabis-grade Mylar bags typically falls in the range of 120 to 180 microns (roughly 4.7 to 7 mil), which provides the puncture resistance needed for sharp bud stems and the barrier performance required for long-term freshness. Thicker is not always better — the key is the right combination of layers, not just raw thickness. For more detail on selecting film gauges, see this Mylar bag thickness guide.
Smell-Proof: The Odor Barrier That Matters
Cannabis odor is one of the most distinctive and persistent smells in retail. Properly constructed smell-proof Mylar bags are engineered so the barrier structure helps limit the movement of aromatic compounds through the packaging.
This matters for three reasons. First, dispensary inventory rooms store hundreds of bags together; without odor containment, the combined smell becomes overwhelming. Second, customers transporting product need discretion. Third, and most importantly for compliance, many state cannabis regulations require packaging to be odor-contained as part of their packaging certification standards.
Child-Resistant: Not Optional
In the United States, cannabis packaging must meet applicable child-resistant requirements. Brands evaluating child-resistant packaging requirements should consider both federal packaging standards and the specific cannabis regulations of the state where the product will be sold.
| Standard | Scope | What It Means |
|---|---|---|
| 16 CFR 1700.20 | U.S. CPSC federal regulation | Packaging must be tested and proven difficult for children under five to open |
| ASTM D3475 | Classification standard for CR packaging | Defines categories and classification approaches for child-resistant package types |
| ASTM D3475 testing | 200 children + 100 seniors | 85% of children must fail to open in 5 minutes; 90% of adults must succeed |
Table: U.S. child-resistant packaging standards applicable to cannabis Mylar bags
For 3.5g Mylar bags, CR compliance is typically achieved through a specialized zipper mechanism that requires a two-step opening action — for example, squeezing a tab while pulling the zipper track. Child-resistant packaging rules in the United States are also connected to the broader framework established under the Poison Prevention Packaging Act. Brands should confirm the exact testing, certification, and labeling obligations that apply to their packaging and market.
A child-resistant Mylar bag is not just a compliance checkbox. It is a safety-focused packaging feature that can help brands address regulatory requirements and reduce accidental access by children.
Custom Branding: Making the 3.5g Bag Yours
The 3.5g Mylar bag is also a billboard. It is the first thing a customer sees on the dispensary shelf, and it is the packaging they carry home. Custom printing transforms a generic barrier pouch into a brand asset.
For custom Mylar bags, packaging specifications can cover size, structure, materials, printing, surface finishes, zipper design, windows, odor-barrier features, and child-resistant configurations. The exact combination depends on the product, brand positioning, target market, and order requirements.
1. Print Methods
Common options include gravure (rotogravure) printing for high-volume orders with up to 10 colors, or digital printing for shorter runs and faster turnaround.
2. Surface Finishes
Surface options can include matte, glossy, soft-touch, holographic, metallic, and other decorative effects to match your brand identity.
3. Bag Styles
Common configurations include stand-up pouches, flat pouches, custom-shaped formats, and windowed designs for product visibility.
4. Compliance Features
Artwork and information layouts can be prepared to accommodate required THC warning symbols, state-specific label content, child-resistant opening options, and tamper-evident features as applicable to the target market. Final packaging and labeling requirements should always be verified for the jurisdiction where the product will be sold.
Sizing Guide: Choosing the Right 3.5g Bag
Not all 3.5g bags are identical. If you are comparing 3.5g Mylar bag size options or choosing a Mylar bag for 3.5 grams of flower, the actual dimensions, style, and features should match the volume and presentation of your product. A broader Mylar bag size guide can also help when comparing different pouch capacities and formats.
| Bag Style | Typical Size | Best For |
|---|---|---|
| Stand-up pouch | 3″ x 5″ (7.6 x 12.7 cm) | Flower display on dispensary shelves |
| Flat pouch | 3″ x 4.5″ (7.6 x 11.4 cm) | Pre-rolls, compact flower packaging |
| Die-cut custom shape | Varies by design | Brand differentiation, novelty products |
| Windowed pouch | 3″ x 5″ with clear window | Showing product without opening |
Table: Common 3.5g Mylar bag styles and their ideal applications
Compliance Across U.S. States
Cannabis packaging regulations vary by state, but the 3.5g Mylar bag format is designed to address common packaging needs across major legal markets. Many states with legal cannabis programs require child-resistant packaging, specific labeling, THC-related warnings, universal cannabis symbols, or other product-specific packaging controls.
Federal child-resistant packaging standards may provide part of the regulatory framework, while individual states can add their own labeling, warning-symbol, material, or packaging requirements. Because requirements vary by product type and jurisdiction and can change over time, brands should verify the final packaging and labeling rules that apply in each market where the product will be sold.
Why Feel U for Your 3.5g Mylar Bags
Feel U (Shenzhen Feel U Packing And Printing Co., Ltd.) is an OEM/ODM custom cannabis packaging manufacturer based in Shenzhen, China, with more than seven years of experience serving the U.S. cannabis packaging market. We work with cannabis brands, cultivation farms, processors, and dispensaries, providing support from packaging concepts, design, material and finish selection, and sampling through manufacturing, quality control, and delivery.
1. Factory-Direct Pricing
As a custom cannabis packaging manufacturer, Feel U operates a factory-direct supply model, helping reduce intermediate procurement steps while supporting both low-volume test orders and larger wholesale production runs.
2. Child-Resistant and Functional Options
For projects that require functional packaging features, Feel U can support child-resistant Mylar bag options as well as resealable zippers, tear notches, smell-proof barrier structures, clear or frosted windows, and other application-specific configurations.
3. Full Custom Design
From concept to production-ready files, Feel U supports custom sizes, structures, materials, printing, surface finishes, artwork adjustment, layout design, and mockup development. Brands can also review our custom packaging service to understand the typical development process from requirements and sampling through final production.
4. Low Minimum Orders
Minimum order quantities can start from 100 pieces, with sample making and pre-production confirmation available to help emerging brands test new packaging and established brands evaluate new SKUs or designs before scaling up.
Ready to Custom-Print Your 3.5g Mylar Bags?
Feel U provides free design support and sample confirmation for custom cannabis packaging projects. Contact our team to discuss your product, target market, quantity, packaging size, structure, printing, and functional requirements.
FAQ
What size Mylar bag is best for 3.5g of flower?
A common 3.5g Mylar bag size is around 3 by 5 inches (7.6 by 12.7 cm), but there is no single universal size. Bud density, bag construction, zipper position, gusset depth, sealing area, and the amount of headspace you want can all affect the final dimensions.
Is a 3.5g Mylar bag the same as an eighth bag?
Yes. In cannabis retail, 3.5 grams is commonly referred to as an eighth, so the terms 3.5g Mylar bag, 3.5 gram Mylar bag, and eighth Mylar bag are often used for the same general packaging format.
Can a 3.5g Mylar bag be used for products other than flower?
Yes. Depending on product dimensions and packaging requirements, the same general pouch format can also be used for pre-rolls, gummies, edibles, shake, and certain concentrate products. The actual capacity depends on product volume rather than weight alone.
Are 3.5g Mylar bags resealable?
Many 3.5g cannabis Mylar bags use a resealable zipper so consumers can open and close the package between uses. Other options can include tear notches, heat-seal areas, child-resistant opening mechanisms, and odor-barrier structures.
Can I customize the dimensions of a 3.5g Mylar bag?
Yes. Custom 3.5g Mylar bags can be developed around the actual volume of your product and your branding requirements rather than relying only on a standard stock size. Dimensions, structure, materials, printing, finishes, zipper configuration, windows, and other functional details can all be specified during packaging development.
Final Thoughts
So, what fits in a 3.5g Mylar bag? Primarily, it is designed to hold an eighth — about 3.5 grams — of dried cannabis flower, although the actual space required varies with flower density and the bag’s construction. The same format can also work for selected pre-roll, edible, concentrate, and other cannabis products when their volume and packaging requirements are taken into account. The right bag combines product fit with freshness protection, functional performance, compliance considerations, and brand presentation.
If you are developing custom 3.5g Mylar bags, Feel U can support size and structure selection, artwork refinement, sampling, printing, manufacturing, quality control, and delivery, with low MOQs starting from 100 pieces. Contact Feel U to discuss your product and packaging requirements and determine the right configuration for your next project.
Sources
- U.S. Consumer Product Safety Commission — 16 CFR Part 1700, Poison Prevention Packaging Act
- ASTM International — ASTM D3475, Standard Classification of Child-Resistant Packages
- National Institute of Standards and Technology — SI units and measurement guidance
- Flexible packaging industry references — common cannabis Mylar bag sizes, barrier-film structures, and laminate specifications
