Spunbond Fabric for Crop Protection: How to Choose the Right GSM

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Introduction: Why GSM Matters in Crop Protection Fabric

Choosing the right spunbond fabric for crop protection is not simply a matter of selecting the thickest or strongest material.

For agricultural covers, GSM affects several important properties at the same time:

• Fabric weight

• Thermal protection

• Light transmission

• Air permeability

• Tensile strength

• Tear resistance

• Handling

• Wind resistance

• Material consumption

• Cost per square meter

This creates an important purchasing trade-off.

A very lightweight fabric may be economical and highly breathable, but it may not provide enough durability for a demanding outdoor environment.

A heavier fabric may offer greater mechanical strength and environmental protection, but it can cost more, weigh more and potentially reduce light transmission or airflow.

Therefore, the right question is not:

“What is the highest GSM available?”

It is:

“What is the lowest GSM that can reliably provide the protection my crop needs?”

This article explains how agricultural buyers can evaluate 17 GSM, 20 GSM, 25 GSM, 30 GSM and heavier spunbond fabrics for crop protection.

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1. What Is Spunbond Fabric for Crop Protection?

Spunbond fabric for crop protection is typically a lightweight polypropylene (PP) nonwoven material designed to create a physical protective layer around crops.

The fabric is manufactured by forming continuous polymer filaments and thermally bonding them into a porous web.

Unlike an impermeable plastic film, spunbond nonwoven fabric allows air to move through its structure.

Depending on the specification, it can help protect crops against:

• Light frost

• Cold temperatures

• Wind

• Insects

• Excessive environmental fluctuation

• Some physical weather exposure

It can also modify the microclimate around plants by affecting heat loss, airflow and moisture conditions.

The actual performance depends on the complete fabric construction rather than GSM alone.

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2. What Does GSM Mean?

GSM means grams per square meter.

It represents the mass of one square meter of fabric.

For example:

GSM	Approximate Weight per m²
17 GSM	17 g
20 GSM	20 g
25 GSM	25 g
30 GSM	30 g
40 GSM	40 g
50 GSM	50 g

A higher GSM generally means more polymer material is present in each square meter.

However, GSM does not directly tell you:

• How strong the fabric is

• How much sunlight passes through

• How much air passes through

• How soft the fabric feels

• How long it will last outdoors

These properties must be evaluated separately.

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3. Why Higher GSM Is Not Always Better

A common purchasing mistake is to assume:

Higher GSM = better crop protection

The relationship is more complicated.

Increasing GSM can potentially improve:

• Mechanical strength

• Tear resistance

• Wind resistance

• Thermal buffering

• Durability

But it can also increase:

• Material cost

• Weight

• Handling requirements

• Fabric density

Depending on construction, higher GSM may also affect:

• Air permeability

• Light transmission

• Moisture behavior

For some crops, a 20 GSM fabric may provide a better overall balance than a 40 GSM fabric.

For another application, 40 GSM may be the more appropriate choice.

The correct GSM depends on the protection objective.

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4. Typical GSM Ranges for Crop Protection

A practical starting point for agricultural buyers is:

GSM	Typical Position	Potential Applications
15–18 GSM	Ultra-light	Short-term lightweight covers
17–20 GSM	Very light	Frost and early-season crop protection
20–25 GSM	Light	General crop covers
25–30 GSM	Medium-light	More demanding weather conditions
30–40 GSM	Medium	Higher durability and stronger environmental protection
40–60+ GSM	Heavy	Specialized covers, wind protection and longer outdoor use

These ranges are illustrative commercial starting points, not universal agricultural standards.

The actual requirement depends on:

• Crop

• Climate

• Temperature

• Wind

• UV exposure

• Protection period

• Installation method

• Required light transmission

• Required air permeability

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5. 17 GSM vs 20 GSM: When Does the Difference Matter?

17 GSM and 20 GSM may look similar, but the 20 GSM fabric contains approximately 17.6% more material per square meter than 17 GSM.

That additional material can provide some additional mechanical and environmental margin.

17 GSM

Potential advantages:

• Very lightweight

• Lower material consumption

• Easy handling

• High breathability

• Lower cost per square meter

Potential limitations:

• Lower mechanical margin

• More vulnerable to tearing during installation

• May be less suitable for windy environments

20 GSM

Potential advantages:

• Still lightweight

• Better mechanical margin

• Suitable for many general crop-cover applications

• Good balance between protection and handling

For buyers who are unsure between 17 and 20 GSM, 20 GSM can be a practical starting point when moderate durability is required.

However, actual tensile and tear data should still be compared.

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6. 20 GSM vs 25 GSM

Moving from 20 GSM to 25 GSM increases the material weight by 25% per square meter.

This can be significant for large agricultural projects.

For example, a project covering:

100,000 m²

would require approximately:

• 2,000 kg at 20 GSM

• 2,500 kg at 25 GSM

The difference is:

500 kg of additional material

Therefore, the extra protection provided by 25 GSM should justify the additional material cost.

20 GSM may be appropriate when:

• Low weight is important

• The environment is relatively moderate

• Shorter protection periods are required

• High airflow is important

25 GSM may be preferred when:

• Greater mechanical durability is needed

• Wind exposure is higher

• The material will be handled repeatedly

• A more substantial protective layer is required

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7. 25 GSM vs 30 GSM

The difference between 25 GSM and 30 GSM becomes even more relevant for large-scale agricultural applications.

For every 100,000 m²:

25 GSM = approximately 2,500 kg

30 GSM = approximately 3,000 kg

That is a difference of:

500 kg

Again, higher GSM should only be selected when the additional performance is actually required.

30 GSM may be attractive for applications requiring:

• Higher tear resistance

• Greater wind resistance

• More robust handling

• Longer service periods

• Stronger environmental protection

But if the crop only needs lightweight frost protection, 30 GSM may be unnecessary.

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8. How GSM Affects Frost Protection

One of the major reasons farmers use spunbond crop covers is frost protection.

The fabric can reduce heat loss from the crop by creating a layer of relatively still air around the plants.

GSM can influence the amount of material and structure available for this protective function.

However, frost performance does not depend on GSM alone.

It also depends on:

• Air permeability

• Fabric thickness

• Installation method

• Ground heat

• Wind speed

• Ambient temperature

• Crop type

• Duration of exposure

Therefore:

30 GSM is not automatically twice as effective as 15 GSM.

The relationship between GSM and frost protection is not linear.

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9. GSM and Air Permeability

Air permeability is particularly important for crop covers.

Plants require air exchange, and excessive restriction can create undesirable conditions under the cover.

As fabric structure becomes heavier or denser, air permeability may change.

However, GSM alone cannot predict the exact airflow.

Two 25 GSM fabrics from different manufacturers may have different:

• Fiber structures

• Bonding patterns

• Thicknesses

• Air permeability values

Therefore, buyers should request an actual air-permeability test result when airflow is critical.

A useful specification is:

Target GSM + target air permeability

rather than:

GSM only

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10. GSM and Light Transmission

Light is another major consideration.

Plants need sufficient light for photosynthesis.

A crop cover therefore needs to provide protection without unnecessarily restricting solar radiation.

A heavier fabric can potentially reduce light transmission depending on its construction.

For applications where sunlight is critical, buyers should evaluate:

• Light transmission

• Fabric color

• GSM

• Thickness

• Fiber structure

This is especially important for long-duration crop covers.

A material that provides excellent physical protection but significantly reduces available light may not be the best agricultural solution.

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11. GSM and Thermal Performance

A heavier fabric can provide a more substantial protective layer, but thermal performance is influenced by the complete fabric structure.

Important factors include:

• GSM

• Thickness

• Porosity

• Air volume within the structure

• Installation

• Wind

• Ambient temperature

The objective is not simply to maximize GSM.

The goal is to create sufficient thermal buffering while maintaining:

• Air exchange

• Light availability

• Practical handling

• Reasonable cost

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12. GSM and Wind Resistance

Wind is one of the biggest mechanical challenges for agricultural crop covers.

A large sheet of fabric can experience substantial forces when exposed to wind.

The relevant properties include:

• Tensile strength

• Tear strength

• Elongation

• Bonding quality

• Fabric width

• GSM

• Installation method

Higher GSM can provide more material and potentially greater mechanical performance, but tensile and tear test results are more meaningful than GSM alone.

For windy regions, ask the supplier for MD/CD tensile and tear data.

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13. GSM and Tear Resistance

Imagine a crop cover develops a small cut during installation.

Wind can cause the cut to propagate.

This is where tear strength becomes important.

A heavier fabric may have greater tear resistance, but the relationship is affected by:

• Fiber orientation

• Bonding pattern

• Fabric structure

• Polymer quality

• Production process

Therefore, a buyer should not assume:

30 GSM always tears less easily than 25 GSM.

Instead, compare actual tear-test results.

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14. GSM and UV Resistance

GSM and UV resistance are related but should not be confused.

A 30 GSM fabric without appropriate UV stabilization may still degrade prematurely outdoors.

A 20 GSM fabric with an appropriate UV-stabilization system may provide a more suitable service life for a specific application.

Outdoor durability depends on:

• UV stabilizer

• UV intensity

• Climate

• Temperature

• Exposure duration

• Fabric construction

• Color

• Mechanical stress

Therefore, for outdoor crop protection, specify:

GSM + UV requirement + expected service period

rather than GSM alone.

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15. How Long Should Crop Protection Fabric Last?

The required service life is one of the most useful questions buyers can answer.

Consider three scenarios.

Short-term protection

The fabric is used for:

• A few days

• A cold-weather event

• Temporary frost protection

A lightweight fabric may be sufficient.

One-season protection

The material remains outdoors for several months.

A more durable specification and UV stabilization may be required.

Multi-season protection

The fabric is expected to survive repeated outdoor exposure.

The buyer may need:

• Higher mechanical performance

• UV stabilization

• Higher tear resistance

• More durable construction

The correct GSM should be selected in combination with these requirements.

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16. Direct Crop Cover vs Supported Cover

Installation method can influence GSM selection.

Direct crop cover

The fabric is placed directly over the plants.

Advantages of lightweight material include:

• Lower weight on plants

• Easier handling

• Flexible installation

• Lower material consumption

Lightweight GSM may therefore be preferable.

Supported crop cover

The fabric is installed over:

• Hoops

• Tunnels

• Frames

• Greenhouse structures

The support structure carries some of the fabric load.

This may allow the buyer to optimize GSM according to wind, durability and installation conditions rather than simply selecting the lightest possible fabric.

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17. GSM Selection by Crop Protection Objective

Protection Objective	Possible GSM Starting Point	Key Properties
Light frost protection	17–20 GSM	Lightweight, breathable
General crop covering	20–25 GSM	Balanced protection
Wind-exposed crop cover	25–30 GSM	Strength and tear resistance
Longer outdoor exposure	25–40 GSM	Durability and UV stabilization
Heavy-duty protection	30–60+ GSM	Strength and service life
Weed-control applications	50–150+ GSM	Durability and coverage

These are starting points rather than fixed industry specifications.

The actual fabric should be validated according to local agricultural conditions.

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18. GSM Selection by Climate

Climate can dramatically change the correct specification.

Mild climate

A lightweight 17–20 GSM fabric may provide sufficient protection.

Moderate climate

20–25 GSM may offer a useful balance.

Windy climate

25–40 GSM may be considered, but tensile and tear properties should be evaluated.

High UV environment

GSM should be considered together with UV stabilization.

Cold climate

Thermal protection becomes more important, but excessive weight may reduce light transmission.

Therefore, climate should always be part of the specification discussion.

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19. Don't Forget Fabric Width

GSM is only one part of the commercial calculation.

Width can significantly influence agricultural installation efficiency.

For example, suppose a farmer needs to cover a 10-meter-wide tunnel.

A suitable wider roll may reduce:

• Number of seams

• Installation time

• Material overlap

• Labor cost

Therefore, the buyer should optimize:

GSM + width + roll length

together.

A slightly more expensive fabric in a more efficient width may produce a lower total installation cost.

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20. Cost Comparison: GSM Has a Direct Impact

When fabric is purchased by kilogram, GSM directly determines material consumption per square meter.

The simplified formula is:

Cost per m² = GSM ÷ 1000 × Price per kg

Assume the price is US$1.50/kg.

GSM	Material Cost/m²
17 GSM	US$0.0255
20 GSM	US$0.0300
25 GSM	US$0.0375
30 GSM	US$0.0450
40 GSM	US$0.0600
50 GSM	US$0.0750

This example demonstrates why GSM optimization matters for large agricultural projects.

At 1 million m², the difference between 20 GSM and 30 GSM is approximately:

10,000 kg of additional material.

At US$1.50/kg, that represents approximately:

US$15,000

of additional material cost.

Therefore, buyers should not automatically move to higher GSM without a clear performance reason.

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21. A Better Way to Compare GSM

Instead of asking:

“Which GSM is strongest?”

use a performance-based comparison.

Factor	20 GSM	25 GSM	30 GSM
Material consumption	Low	Medium	Higher
Handling	Very easy	Easy	Moderate
Airflow potential	High	High–medium	Medium
Light transmission potential	High	High–medium	Medium
Mechanical margin	Moderate	Higher	High
Wind resistance potential	Moderate	Higher	High
Material cost/m²	Low	Medium	Higher
Suitable protection level	Light	General	More demanding

The actual performance must be confirmed by technical testing because GSM does not uniquely determine the other properties.

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22. A Practical Decision Tree

Use the following decision process when selecting spunbond fabric for crop protection.

Question 1: What are you protecting against?

Frost → prioritize thermal buffering.

Wind → prioritize tensile and tear strength.

Insects → prioritize barrier characteristics and appropriate opening structure.

UV exposure → prioritize UV stabilization.

Multiple threats → balance all major properties.

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Question 2: How long will the fabric stay outdoors?

Days/weeks → lightweight material may be sufficient.

One season → consider durability and UV stabilization.

Multiple seasons → place greater emphasis on outdoor aging and mechanical retention.

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Question 3: How much airflow is required?

If airflow is critical, request an air-permeability specification.

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Question 4: How much light is required?

If the crop requires high solar transmission, evaluate actual light-transmission data.

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Question 5: How windy is the location?

If wind is significant, compare tensile and tear properties rather than GSM alone.

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Question 6: What is the target cost?

Calculate:

GSM × price/kg = material cost/m²

Then compare the total cost against expected service life.

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23. Example: Selecting Fabric for Strawberry Frost Protection

Suppose a strawberry grower needs temporary protection during a cold period.

The requirements are:

• Lightweight

• Good light availability

• Breathable

• Easy to install

• Moderate frost protection

• Short-term use

A reasonable starting comparison could be:

17 GSM vs 20 GSM

If the 17 GSM fabric provides sufficient tensile strength and durability for the installation conditions, it may offer the lowest material consumption.

If wind or repeated handling creates greater mechanical risk, 20 GSM may provide a more comfortable performance margin.

The decision should be based on sample testing rather than GSM alone.

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24. Example: Selecting Fabric for Wind-Exposed Vegetable Fields

Now consider a vegetable field exposed to strong wind.

The buyer may compare:

25 GSM vs 30 GSM

The priorities become:

• Tensile strength

• Tear resistance

• Elongation

• Bonding quality

• UV resistance

• Secure installation

In this situation, 30 GSM may be justified if its additional mechanical performance significantly improves field durability.

But if a 25 GSM fabric has substantially better tensile/tear performance due to its construction, it may still be the better solution.

Again:

Test data beats GSM assumptions.

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25. Example: Selecting Fabric for Long Outdoor Use

Suppose the fabric must remain outdoors for several months.

The buyer should not simply request:

“40 GSM agricultural spunbond.”

Instead, the specification could include:

• 30–40 GSM

• Virgin PP

• White

• Defined MD/CD tensile

• Defined tear strength

• Defined air permeability

• Defined light transmission

• UV stabilization

• Required outdoor service period

• Required width

• Roll length

This produces a much more useful supplier quotation.

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26. What Should Be Included in an Agricultural Crop Cover RFQ?

A professional RFQ can look like this:

Product: PP spunbond nonwoven fabric for crop protection
Application: Frost/crop protection
Target GSM: 20–25 GSM
Color: White
Width: 3.2 m
Raw material: Virgin PP
UV stabilization: Required
Air permeability: Please provide test value
Light transmission: Please provide test value
MD/CD tensile strength: Please provide
Tear strength: Please provide
Water behavior: Rain-permeable
Expected outdoor use: [X weeks/months]
Roll length: [X meters]
Quantity: [X tons / containers]
Destination: [Port]
Please provide: TDS, sample, packing details, lead time and quotation.

This gives the supplier enough information to recommend the most appropriate construction.

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27. Common Mistakes When Choosing GSM

Mistake 1: Automatically Choosing the Highest GSM

More material does not automatically mean better crop performance.

Mistake 2: Selecting GSM Based Only on Price

A cheaper low-GSM material may have insufficient durability.

Mistake 3: Ignoring UV Stabilization

Outdoor degradation can become a major problem.

Mistake 4: Ignoring Air Permeability

Crop covers need an appropriate airflow balance.

Mistake 5: Ignoring Light Transmission

Plants still need sunlight.

Mistake 6: Looking at Tensile Strength but Not Tear Strength

A small cut can propagate under wind stress.

Mistake 7: Ignoring Width

Poor width selection can increase installation labor and material waste.

Mistake 8: Buying Without Field Testing

Actual agricultural conditions are difficult to reproduce completely in a laboratory.

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28. GSM Is Only One Part of the Specification

A professional crop-protection specification should ideally include:

Physical

• GSM

• Thickness

• Width

• Roll length

Mechanical

• MD tensile

• CD tensile

• MD elongation

• CD elongation

• Tear strength

Functional

• Air permeability

• Light transmission

• UV resistance

• Water behavior

• Thermal performance where relevant

Production

• Raw material

• Bonding structure

• Color

• Surface treatment

Logistics

• Roll diameter

• Core size

• Roll weight

• Packaging

This complete specification is much more useful than simply saying:

“25 GSM agricultural fabric.”

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29. How to Choose Between 20, 25 and 30 GSM

For buyers who need a simple starting framework:

Choose around 20 GSM when:

• Lightweight construction is important

• The cover is temporary

• Moderate protection is required

• Airflow and light are priorities

• Weather conditions are relatively mild

Consider around 25 GSM when:

• You need a balance between weight and durability

• The cover will be used for a longer period

• Moderate wind exposure exists

• General-purpose crop protection is required

Consider around 30 GSM when:

• Higher mechanical durability is needed

• Wind exposure is significant

• Repeated handling is expected

• A more robust protective layer is required

But these are starting points.

The final decision should be based on actual tensile, tear, air-permeability, light-transmission and UV requirements.

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30. Final Buyer Checklist

Before purchasing spunbond fabric for crop protection, confirm:

Crop

• What crop is being protected?

• What growth stage is involved?

Threat

• Frost?

• Wind?

• Insects?

• Excessive sunlight?

• Multiple environmental stresses?

GSM

• 17 GSM?

• 20 GSM?

• 25 GSM?

• 30 GSM?

• Higher?

Environment

• Temperature range

• Wind

• UV intensity

• Rainfall

• Expected exposure period

Performance

• Air permeability

• Light transmission

• Tensile strength

• Tear strength

• Elongation

• UV resistance

Logistics

• Width

• Roll length

• Roll weight

• Packaging

• Container loading

Economics

• Price/kg

• Cost/m²

• Expected service life

• Installation cost

• Replacement cost

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FAQ

What GSM is best for spunbond fabric for crop protection?

There is no universal best GSM. Around 17–20 GSM can be suitable for lightweight temporary protection, while 20–30 GSM is a useful starting range for many general crop-cover applications. Heavier fabrics may be appropriate for demanding wind or longer-term applications.

Is 20 GSM enough for frost protection?

It can be, depending on the crop, temperature, wind, installation method and required protection level. GSM alone cannot determine frost-protection performance.

Is 30 GSM better than 20 GSM?

Not necessarily. 30 GSM contains more material and may provide a greater mechanical margin, but it also costs more and weighs more. If 20 GSM already meets the application's requirements, 30 GSM may provide little additional commercial value.

Does higher GSM mean better UV resistance?

No. UV resistance depends heavily on the stabilization system and exposure conditions. A higher-GSM fabric without suitable UV stabilization can still degrade outdoors.

Does higher GSM reduce air permeability?

It can, depending on the fabric structure, but GSM alone does not determine air permeability. Actual test data should be used when airflow is important.

What is the difference between 20 GSM and 25 GSM?

25 GSM contains 25% more material per square meter than 20 GSM. It may provide greater mechanical and environmental performance, but the additional cost should be justified by the application.

What GSM is suitable for windy agricultural areas?

Around 25–40 GSM can be considered as a starting range for more demanding conditions, but buyers should focus on actual tensile and tear strength, bonding quality and installation rather than selecting GSM alone.

Does crop protection fabric need to be waterproof?

Usually not. Many crop covers need to remain breathable and allow appropriate moisture movement. The required water behavior depends on the crop and protection objective.

How do I calculate the cost of agricultural spunbond fabric?

When the supplier quotes by kilogram:

Cost per m² = GSM ÷ 1000 × Price per kg

This allows buyers to compare the material cost of different GSM options.

Should I test samples before buying a container?

Yes. For commercial agricultural projects, sample testing is strongly recommended. Ideally, evaluate both laboratory properties and actual field performance before placing a large order.

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Conclusion

Choosing spunbond fabric for crop protection is fundamentally a balancing exercise.

The objective is not to find the heaviest fabric.

It is to find the minimum GSM that provides sufficient protection, durability and service life without creating unnecessary material cost or compromising airflow and light availability.

For many buyers, 17–20 GSM can be a starting point for lightweight temporary protection, 20–25 GSM can provide a useful general-purpose balance, and 25–40 GSM or higher may be appropriate for more demanding outdoor conditions.

But GSM should always be evaluated together with:

Air permeability + light transmission + tensile strength + tear strength + UV resistance + climate + service life + cost

The best crop-protection fabric is therefore not necessarily the thickest fabric.

It is the fabric that delivers the right agricultural performance at the lowest practical total cost.