Most kraft paper failures are not caused by "weak paper." They happen because the paper was specified by weight alone, or because a humid warehouse, a sharp-edged part or a folding direction was never considered. This guide explains how to read industrial kraft paper specifications, match a grade to the job, and decide when a coating is worth paying for.
The short version
- Treat the following weights as starting points to validate with a trial, not rules. Light wrapping and interleaving often start at 60–90 gsm. Bags, carton linings and general protection often sit at 90–150 gsm. Heavy or sharp-edged goods and pallet layers often need 150–220 gsm.
- Ask for tensile, tear and burst values in both machine direction (MD) and cross direction (CD), with the test method named.
- Add a coating only when you can name the failure it prevents: moisture (PE), humidity and abrasion (wax), or rust (VCI).
- Always test a sample roll on your own line before committing to volume.
What industrial kraft paper actually is
Kraft paper is made from wood pulp using the kraft process, which keeps long fibers intact. That fiber length explains its high tensile strength and tear resistance. "Industrial" kraft is the version bought by weight, width and tested strength, as opposed to decorative or craft kraft. TGX Group supplies it as virgin or recycled kraft in natural brown, bleached white or coated finishes.
The two choices that matter first are fiber source and surface:
- Virgin kraft usually gives higher and more consistent strength per gram. Choose it for sacks, heavy wrapping and anything that runs on fast automated equipment.
- Recycled kraft can be a strong choice for void fill, interleaving, pallet layers and general wrapping, where cost and recycled content matter more than peak strength. Strength is typically lower and more variable, so verify with samples.
- Natural brown, bleached white or coated is mostly a print, appearance and barrier decision. It is not a strength decision.
If you are looking for lighter-duty kraft for retail, gift or household wrapping, see our standard kraft paper, an uncoated brown roll in the 65–150 gsm range. It sits within our wider Other Packaging & Wrapping range, alongside glassine and medical packaging papers.
Specifications at a glance
These are the ranges TGX Group lists for its industrial kraft paper. Exact values depend on grade, so request the datasheet for the grade you are considering.
| Parameter | Range or options | What it means in practice |
|---|---|---|
| Basis weight | 40–300 gsm. Standard grades: 60, 70, 90, 120, 150, 180, 220 gsm | Weight sets the ceiling for strength, but the fiber and the process decide how close you get to it. |
| Tensile strength | 5–12 kN/m (varies by grade) | Resistance to being pulled apart, such as on a winding line or under a load in a bag. |
| Burst strength | 2–9 kPa·m²/g | Resistance to pressure from the face of the sheet, such as a heavy part pressing into a liner. Expressed per gram, so it is an index. |
| Tear resistance | 150–800 mN | How easily a nick or cut spreads. Important for sharp-edged goods and stitched or punched seams. |
| Roll widths | 300–2500 mm, custom | Order the width your machine uses, to avoid trim waste. |
| Core diameter | 3″, 6″ or tailored; sheets also available | Must match your unwind shaft or dispenser. |
| Surface options | Uncoated, PE coating, wax coating, anti-rust (VCI) treatment | See the coating section below. |
How to read the strength numbers without being misled
1. Compare strength per gram, not strength alone
A heavier sheet will almost always test stronger, so raw tensile numbers from different weights tell you little. Convert to an index by dividing tensile strength (kN/m) by grammage (g/m²) and multiplying by 1,000 to get N·m/g. For example, a 100 gsm sheet with 9.0 kN/m tensile has an index of 90 N·m/g. That lets you judge whether a lighter, cheaper grade can do the same job as a heavier one. If a supplier's lighter grade gives a similar index with the same fiber type, you may be able to cut weight.
2. Always ask for MD and CD values
Paper is stronger along the direction it ran through the paper machine (MD) than across it (CD). Industry buying guides recommend requesting both directions for tensile, tear and similar properties, because a single number hides the weaker direction [1]. This also explains TGX Group's converting advice: when making bags or cartons, align the folding direction with the paper grain for best strength.
3. Match the test to the failure mode
Burst strength is still common in specifications, but tensile and tensile energy absorption (TEA) are often better predictors of how sack and web-handling applications actually fail [1]. A paper sack manufacturer's handbook describes TEA as the main property for estimating sack wall strength, and notes that it correlates with drop-test results. The same handbook points out that tear strength matters most where needle holes or cuts act as starting points for a tear [2].
| Property | Common test methods | Prioritize it when… |
|---|---|---|
| Grammage | ISO 536 | Always. Include the tolerance (for example ±5%) in your purchase specification. |
| Tensile strength and TEA | ISO 1924-2 or ISO 1924-3; TAPPI T 494 | The paper is pulled on machines, or forms bags and sacks that take drops. |
| Tear resistance | ISO 1974; TAPPI T 414 | Wrapping sharp-edged parts, or sewing, punching or perforating the paper. |
| Burst strength | ISO 2758; TAPPI T 403 | The sheet is a liner or layer pressed on by heavy goods. |
| Moisture and water uptake | ISO 287 (moisture content); ISO 535 (Cobb) | Rolls are stored in humid conditions, or the packed goods sweat or are damp. |
One practical detail: ISO 1924 has more than one part, and they use different test speeds (part 3, for example, uses 100 mm/min) [3]. When comparing quotes, ask which part and which method code each supplier used. Naming the method in your specification removes room for interpretation [4].
Matching kraft paper to the job
The weights below are practical starting points for trials. Your product, handling and line speed decide the final choice.
Protective wrapping and interleaving
Metal parts, automotive components and furniture need surface protection and abrasion resistance. Start around 60–120 gsm, and move up when edges or burrs could cut through, which is when tear resistance becomes the number to check. For steel or iron parts stored for weeks or months, consider VCI-treated kraft (see below).
Bags, envelopes and carton linings
E-commerce and retail bags usually sit in the middle of the range, around 70–120 gsm. Printability and a smooth surface matter as much as strength here, since logos, handling marks and traceability labels are often printed directly on the paper.
Multi-wall sacks for powders and granules
Chemicals, building materials and agricultural products put the most dynamic stress on paper. Prioritize TEA and tear in both directions, and ask about wet-strength treatment if sacks are stored outdoors or in humid conditions.
Pallet layers, tubes, cores and edge protectors
These are structural or load-bearing uses, typically 150–220 gsm or more, where stiffness, burst and consistent thickness matter more than printability. TGX Group also supplies kraft as a raw material for corrugated board and as a laminating substrate for composite packaging.
Our kraft is used across logistics, e-commerce, food and agriculture, automotive and machinery, chemicals and building materials, converting, and furniture. See the full list on our Industries page. For direct food contact, requirements differ by grade and region, so review our food packaging papers and request compliance documents for your market.
Surface treatments: when a coating is worth it
Every treatment solves one problem and can create another. Use this table to decide whether you actually need one.
| Option | Best for | Watch out for |
|---|---|---|
| Uncoated natural | Dry, indoor use; simple recycling; good printing and gluing | Loses strength when damp; absorbs moisture and oils. |
| PE coating | Moisture protection; heat-sealable constructions | May change how the paper is handled at your local recycler. Confirm before making recyclability claims. |
| Wax coating | Humidity and abrasion resistance during storage and transport | Can affect gluing and printing. Test adhesives and inks first. |
| Anti-rust (VCI) | Wrapping steel and iron parts for storage and shipping | Metal compatibility and cleanliness requirements (see below). |
Using VCI kraft correctly
VCI paper releases vapor that forms a protective layer on metal, but it does not work on everything. Many VCI papers are made for ferrous metals only, and some suppliers advise against using them with items containing nickel. Multi-metal versions exist [5]. Parts should be clean, dry and free of corrosion before wrapping, because VCI packaging helps prevent corrosion but does not remove it [6]. Wrap completely rather than loosely covering, since the vapor needs an enclosed space to do its job. One vendor's guidance is roughly one square foot of paper per cubic foot of packaged volume [5]. Treat that as a rule of thumb and confirm the figure for your grade.
Because VCI performance depends on the chemistry, tell us which metals you ship and for how long. Our team can confirm what is available, and whether you need a specific military or industry specification.
Storage, handling and running the paper
Paper is hygroscopic, meaning it takes up and releases moisture, and that changes both strength and how flat it runs. These recommendations follow TGX Group's product guidance:
- Store rolls in a cool, dry area away from direct sunlight, and avoid high humidity.
- Store rolls horizontally on stable supports, and use proper lifting tools for heavy rolls.
- Protect roll edges from impacts, since a damaged edge is where web breaks tend to start.
- Set correct tension on automated machines. For lamination or printing, adjust temperature and pressure to the grade.
- Run a short trial with the actual adhesive, ink or coating you plan to use before scaling up.
A common shop-floor habit that helps: let rolls move from a cold warehouse to the production area and settle to room conditions before unwrapping them. This reduces condensation and curling.
Sustainability: what you can and cannot claim
Kraft paper is biodegradable and recyclable, and uncoated grades are compatible with standard industrial waste-paper streams. Paper recycling is also mature at a system level. The European Paper Recycling Council reported a 71.4% recycling rate for 2021 and has committed to a 76% target for 2030 [7] [8]. Rates differ by region and by how they are measured, so use local figures in your own reporting.
Be careful with claims on coated grades. A PE or wax coating can change how a recycler treats the paper, so confirm local acceptance before you label a coated product as recyclable. If FSC-certified fiber matters to your customers, ask for the certificate details with your order. You can read more about our approach on the Sustainability page.
How to write a specification that gets the right paper
A clear request gets a faster, more accurate quote. Send the following:
- Application: what you are wrapping or making, its weight, and whether edges are sharp.
- Fiber and finish: virgin or recycled; brown, white or coated.
- Weight and tolerance: gsm with tolerance.
- Strength targets: minimum tensile, tear and burst in MD and CD, with the test method code.
- Environment: storage humidity, outdoor exposure, and metal types if VCI is needed.
- Format: roll width, core diameter and roll outer diameter, or sheet size.
- Process: printing, gluing, lamination or bag-making method.
TGX Group's ordering flow is simple: define requirements, request a datasheet, approve a sample on your line, then place the order. Batches go through quality inspection before shipment, and our Quality Control page describes raw-material, in-process and finished-product testing and references ISO 9001. If your project needs certificates or test reports, ask for them when you request a quote. We support both small trial batches and large-volume purchasing.
Common mistakes to avoid
- Buying by gsm alone. Two papers at the same weight can differ widely in tensile and tear. Compare indexes and ask for MD and CD data.
- Over-specifying weight. A heavier sheet costs more per square meter and per shipment. Test whether a lighter grade with good tear performance does the job.
- Ignoring grain direction. Folding against the grain weakens bags and cartons.
- Using VCI on the wrong metal. Confirm compatibility, and clean parts first.
- Skipping the line trial. Adhesives, inks and heat behave differently on different papers.
Frequently asked questions
What GSM should I choose for industrial kraft paper?
There is no single answer. Light wrapping often starts around 60–90 gsm, bags and linings around 90–150 gsm, and heavy-duty or structural uses at 150–220 gsm or higher. Confirm with a sample trial, since fiber type and tear strength can matter as much as weight.
Is recycled kraft as strong as virgin kraft?
Usually not at the same weight, because recycled fibers are shorter. It can be the right choice for void fill, interleaving and general wrapping. For sacks or fast automated lines, virgin kraft is the safer choice. Compare tested values rather than assuming.
Can kraft paper handle humid conditions?
Standard kraft loses strength in high humidity. Options include wet-strength treatment, PE coating or wax coating, depending on whether the risk is occasional dampness or constant moisture. Good storage helps as well.
Does VCI kraft paper work on all metals?
No. Many grades are intended for ferrous metals, and some are not recommended for parts containing nickel. Multi-metal grades exist. Tell your supplier which metals you ship so the right chemistry is chosen.
Can I order custom widths and sheet sizes?
Yes. TGX Group supplies rolls from 300 mm to 2500 mm wide, in 3″ or 6″ cores or tailored cores, and custom sheet sizes.
