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Custom Kraft Paper Flat Bottom Bags
Bring together the visual warmth of kraft paper, a stable flat bottom and a material structure selected for your product. Cailyn offers custom kraft paper flat bottom bags for coffee, powders, tea, snacks and other dry foods.
Choose from conventional Kraft/PE laminates or explore structures incorporating PLA, cellulose barrier films and PBAT-based sealing films for projects with compostability goals. Each option balances appearance, protection, flexibility and end-of-life requirements differently.
Natural Kraft Appearance, Practical Shelf Presentation
Kraft paper gives packaging a distinctive fiber pattern and an understated appearance that works with simple logos, bold typography and colorful artwork.
The flat bottom format provides a stable base when properly filled, while the front, back and side panels offer space for branding, product information and preparation instructions.
Customize the dimensions, printing and opening features to suit your product and the way customers use it.
- Distinctive kraft paper appearance
- Flat base for upright presentation
- Multiple panels for branding and product information
- Material options for different protection requirements
- Optional closures and coffee valves, subject to construction
Custom Printed Kraft Flat Bottom Bags with Tailored Barrier Layers, PLA Zippers and PLA Degassing Valves
Choose the Material Structure Around Your Product
Kraft Paper / PE: Paper Character with a Conventional Sealing Layer
Kraft/PE combines the appearance and body of paper with a polyethylene inner layer for heat sealing and moisture protection.
It is an option for brands seeking a paper-based appearance while retaining a conventional plastic sealing layer. The paper contributes part of the bag’s structure, allowing a lower plastic proportion in some designs compared with an equivalent all-plastic construction.
Any plastic-reduction claim should be based on a comparison of actual material weights. Kraft/PE still contains conventional PE and should not be described as fully biodegradable or compostable.
Kraft Paper / PLA: An Alternative to the Conventional PE Layer
Kraft/PLA replaces the conventional PE film with a PLA-based layer. It offers a material route for brands developing kraft packaging with compostability goals.
This structure should be selected according to the product’s moisture sensitivity, filling conditions and intended storage period. Replacing PE with PLA does not automatically deliver the same sealing or barrier performance.
Compostability claims must be supported for the complete finished bag under specified conditions, rather than inferred from the paper and PLA components alone.
Cellulose Barrier Films: More Options for Sensitive Products
For powders and other products requiring additional protection, cellulose-based barrier films provide further design options.
In the proposed structures below, NK refers to the specified transparent cellulose barrier film, while NKME refers to the specified metallized cellulose film. Exact grades and properties are confirmed during material selection.
A transparent barrier film allows the kraft layer to remain visible when used on the outside, although the surface feel will differ from exposed paper. A metallized internal layer can be considered when greater light protection and additional barrier performance are required.
PBAT-Based Films: Flexibility and Toughness
PBAT is a flexible biodegradable polyester that can be used in suitable compostable film formulations.
In a kraft laminate, a PBAT-based film can contribute flexibility, toughness and sealing functionality. The kraft paper and overall construction provide much of the bag’s body and support.
For heavier products, we evaluate the complete structure—including paper weight, film thickness, seals and bottom design—rather than relying on one material to provide all the required strength.
Material Combinations to Discuss
The following structures are development options, listed from outside to inside. Final grades, thicknesses and layer order are confirmed for each project.
| Material Structure | Main Design Purpose | Applications to Evaluate |
|---|---|---|
| Kraft / PE | Kraft appearance with a conventional heat-sealing layer | Dry foods with suitable barrier requirements |
| Kraft / PLA | Replace conventional PE with a PLA-based layer | Selected dry foods and projects targeting compostability |
| Kraft / NK / PLA | Combine an exposed kraft exterior with a cellulose barrier layer and PLA-based sealant | Tea, dry blends and selected powders |
| NK / Kraft / PBAT | Combine an outer cellulose film, paper body and flexible PBAT-based sealing layer | Products requiring a balance of appearance and toughness |
| NK / Kraft / NKME / PBAT | Add a metallized cellulose barrier layer to a paper-based construction | Coffee and powders with more demanding protection needs |
The PLA- and PBAT-containing combinations are candidates for compostable packaging development. Finished-pack performance and compostability must be verified for the selected specification.
Packaging for Coffee, Powders and Dry Foods
Coffee
Kraft flat bottom bags offer a structured presentation for roasted coffee beans and ground coffee. Material selection should consider oxygen, moisture and aroma protection, as well as any degassing valve requirement.
For a compostability project, the valve and closure need to be considered alongside the laminate.
Powders and Drink Mixes
Powdered products can require careful moisture protection to help limit clumping. Some formulations also need additional protection from oxygen or light.
We can evaluate cellulose barrier and metallized cellulose options according to your formulation, target shelf life and distribution conditions. Filling trials should also check whether powder contamination affects the seals.
Tea and Herbal Blends
Choose a kraft presentation with a structure selected for moisture and aroma protection. Dimensions can be adapted to the volume of loose-leaf tea or herbal blends rather than filling weight alone.
Snacks and Other Dry Foods
Nuts, granola and other dry foods have different protection needs. Oil content, moisture sensitivity and storage conditions help determine whether a simpler structure is sufficient or an additional barrier layer is needed.
Customization Options
| Item | Options |
|---|---|
| Bag Format | Flat bottom bag with side gussets |
| Dimensions | Custom width, height and gusset depth |
| Paper | Kraft grade and weight selected for the project |
| Material Structure | Kraft/PE, Kraft/PLA and selected cellulose-based laminates |
| Printing | Custom logo, artwork and product information |
| Closures | Options assessed against material compatibility and end-of-life goals |
| Coffee Valve | Available for suitable constructions; specification confirmed separately |
| Surface Appearance | Exposed kraft or a film-covered kraft appearance, depending on layer order |
| Order Quantity | Quoted according to material, size, printing and accessories |
Select Protection Before Finalizing the Material
The best kraft bag is the one that protects your product while meeting your packaging goals.
Share your product type, filling weight, target shelf life and shipping conditions. We can then discuss the required moisture and oxygen barrier, sealing performance and mechanical strength.
Where needed, material data and packaging trials can help compare options. No fixed shelf life should be assumed from the material names alone.
PLA Zippers and PLA Degassing Valves
Cailyn offers PLA zipper and PLA one-way degassing valve options for kraft flat bottom bags developed with compostability goals.
PLA Resealable Zippers
Allow customers to open and reclose the bag between uses. Available for suitable constructions used for coffee, tea, powders and dry foods.
PLA One-Way Degassing Valves
Allow gas released by roasted coffee to escape while helping limit outside air entry. They provide an alternative to conventional valve options when developing a compostable coffee packaging system.
By considering the laminate, zipper and valve together, we can help you develop a more complete packaging specification. Component compatibility, sealing performance and finished-bag compostability must be confirmed for the selected construction.
| Item | Options |
|---|---|
| Closure | PLA resealable zipper available for compatible bag constructions |
| Coffee Valve | PLA one-way degassing valve available for roasted coffee packaging |
| Compostability | Evaluated for the complete bag, including films, paper, adhesives, inks, zipper and valve |
Frequently Asked Questions
Q：Can I add a zipper and coffee valve to a bag designed for compostability?
Yes. Cailyn offers PLA resealable zippers and PLA one-way degassing valves for suitable kraft bag constructions. These options allow us to consider the bag body and accessories together when developing the packaging. The use of PLA components alone does not establish finished-bag compostability; the complete package must be verified under the intended composting conditions.
Q：Are all kraft paper bags biodegradable?
No. Kraft bags often contain films, adhesives and accessories. A Kraft/PE bag contains conventional polyethylene and is not a fully compostable construction.
Q：Can Kraft/PLA bags be described as 100% biodegradable?
That claim should not be made from the material combination alone. The complete finished bag and the relevant degradation or composting conditions need supporting evidence.
Q：What is the difference between NK and NKME?
For the structures discussed here, NK identifies a transparent cellulose barrier film and NKME identifies a metallized cellulose film. Confirm the exact supplier grades when comparing technical performance.
Q：Does PBAT make the bag stand more firmly?
PBAT mainly contributes flexibility and toughness. Standing performance depends on the paper, total construction, bottom geometry and how the bag is filled.
Q：Will every structure have the same kraft paper feel?
No. A structure beginning with kraft paper can provide an exposed paper surface. A structure beginning with a cellulose film retains the paper’s appearance beneath a film surface.
Q：Can I add a zipper or coffee valve to a compostable packaging design?
Potentially, but the accessory must be evaluated as part of the finished package. A conventional zipper or valve should not be assumed compatible with the intended compostability claim.
Develop Your Custom Kraft Flat Bottom Bag
Whether your priority is kraft paper appearance, reduced conventional plastic use or a compostable packaging project, Cailyn can help you compare material routes around your product’s needs.
Send us your product details, dimensions, quantity, artwork and target market. We will help you review the structure, printing and sample options.
Contact Cailyn for material guidance, samples and a custom quotation.
