Waterproof & Breathable Principles of Softshell Jackets: What Do 10,000mm Hydrostatic Head and 8,000g MVTR Really Mean?
Jun 12, 2026
1. Introduction: The "Contradictory Demands" of Softshell Jackets
Softshell jackets are among the most common categories in tactical clothing and outdoor gear. They are widely used in military/police duty, outdoor hiking, and daily commuting because they must satisfy two seemingly contradictory requirements:
1. Waterproofing: Preventing water from penetrating the garment in rain or snow
2. Breathability: Expelling sweat vapor during strenuous activity to avoid dampness and chill inside
If a jacket is waterproof but not breathable, body moisture condenses inside, leading to the awkward situation of "heavy rain outside, light rain inside." If it is breathable but not waterproof, it is just an ordinary outer layer that cannot handle bad weather.
Hydrostatic head and MVTR are the quantitative measures of these two capabilities. This article explains what these parameters mean, how they are tested, and their practical significance in the field.
2. Hydrostatic Head: The Quantitative Standard for Waterproofness
2.1 What Is Hydrostatic Head?
The hydrostatic head test (ISO 811 or AATCC 127) measures a fabric's resistance to water penetration. The test procedure is as follows:
1. A fabric sample is clamped between two fixtures
2. A pressurized chamber containing distilled water is placed beneath the sample
3. Water pressure is increased at a rate of 60 cmH₂O per minute
4. The pressure at which a third drop of water appears on the fabric surface is recorded (in mm H₂O)
In simple terms: A hydrostatic head of 10,000 mm means the fabric can withstand the pressure of a 10-meter water column without leaking.
2.2 Protection Levels Corresponding to Different Hydrostatic Head Ratings
| Hydrostatic head range | Protection level | Suitable scenarios | Typical products |
|---|---|---|---|
| <3,000 mm | Water‑resistant | Light rain (<5 min) | Regular windbreakers, lightweight jackets |
| 3,000‑5,000 mm | Rainproof | Moderate rain (15‑30 min) | Entry‑level rainwear, lightweight shells |
| 5,000‑8,000 mm | Moderate to heavy rain protection | Sustained rain (1‑2 hours) | Mid‑range outdoor shells |
| 8,000‑10,000 mm | Stormproof | Heavy rain, pr₂₂olonged exposure | Tactical softshells, military rainwear |
| 10,000‑20,000 mm | High‑pressure water resistant | Heavy rain + wind‑driven impact | Professional mountaineering suits, Gore‑Tex Pro |
| >20,000 mm | Professional waterproofing | Extreme weather | Military grade, expedition gear |
2.3 What 10,000 mm Hydrostatic Head Means in Real - World Use
10,000 mm hydrostatic head is the common standard for tactical softshell jackets and the main focus of this article. It means:
- Stormproof: Withstands 5-10 times the water pressure of a typical umbrella
- Impact resistant: Running or cycling through rain does not cause leakage from water impact pressure
- Load-bearing integrity: Even with backpack straps pressing against the fabric, waterproofing remains intact
Practical test comparisons:
- Ordinary DWR coating: Begins wetting out after 5 minutes of rain, leaks after 15 minutes
- 5,000 mm hydrostatic head: Localized leakage after 30 minutes of moderate rain
- 10,000 mm hydrostatic head: Remains dry after 2 hours of heavy rain (50‑100 mm/24h)
3. MVTR (Moisture Vapor Transmission Rate): The Quantitative Standard for Breathability
3.1 What Is MVTR?
MVTR measures how many grams of water vapor pass through one square meter of fabric in 24 hours. The unit is g/m²/24h.
Test method (using JIS L1099 B1 inverted cup method as example) :
1. A cup is filled with water to the brim
2. The fabric is sealed over the cup mouth
3. The cup is inverted so water contacts the fabric directly
4. Placed in a constant temperature/humidity chamber (40℃, fixed humidity gradient)
5. After 24 hours, the cup is weighed to calculate the weight of water vapor that passed through the fabric
3.2 Comfort Levels Corresponding to Different MVTR Ratings
| MVTR range | Comfort level | Suitable activity intensity | User experience |
| <3,000 | Stuffy | Sitting, walking | Underwear damp after 30 minutes |
| 3,000‑5,000 | Basically comfortable | Low‑intensity hiking | Slightly moist after 1 hour |
| 5,000‑8,000 | Comfortable for moderate activity | Loaded marching, skiing | Dry for 2‑3 hours |
| 8,000‑12,000 | Comfortable for high activity | Running, climbing | No noticeable dampness for 4‑6 hours |
| >12,000 | Professional grade | High‑intensity cardio | Dry all day |
3.3 What 8,000 g/m²/24h MVTR Actually Means
8,000 g/m²/24h means that one square meter of fabric can transmit 8 kg of water vapor in 24 hours. Converting to human sweat output:
- Adult male during moderate-intensity activity (e.g., load-bearing march with 15 kg): sweats approximately 300-500g per hour
- A softshell jacket covers about 1.2 m²
- 8,000 g ÷ 24 hours ÷ 1.2 ≈ approximately 278g of water vapor transmitted per hour
This value is slightly lower than moderate - activity sweat output (300-500 g/h). Therefore, when paired with a moisture - wicking base layer (which spreads sweat quickly), the system can maintain dryness for 2-3 hours – sufficient for most tactical mission scenarios.
4. How Waterproof & Breathable Performance Is Achieved: Membrane Technology
Ordinary coatings (such as PU coatings) cannot simultaneously achieve 10,000 mm hydrostatic head and 8,000g MVTR. To achieve this "contradictory performance" ,functional membranes are required.
There are two mainstream membrane technologies: hydrophilic non-porous membranes and microporous membranes.
4.1 Hydrophilic Non-Porous Membrane
Representative material: Hydrophilic TPU (thermoplastic polyurethane)
How it works:
- The membrane itself has no pores; liquid water molecules cannot pass through
- The membrane material has hydrophilic groups (e.g., hydroxyl-OH) that adsorb water vapor molecules
- Water vapor molecules "jump" from the high-humidity side (inside the garment) to the low - humidity side (outside) via molecular diffusion
Advantages:
- Completely waterproof (no pores, liquid water cannot pass)
- Good wash durability (the non‑porous structure is not easily damaged by detergents)
- Relatively low cost
Disadvantages:
- Lower MVTR (depends on humidity gradient)
- Stiffer hand fee
4.2 Microporous Membrane
Representative materials: ePTFE (expanded polytetrafluoroethylene, the core material of Gore-Tex), microporous PU
How it works:
- The membrane surface contains millions of micropores, approximately 0.2-0.5 microns in diameter
- The smallest water droplets are about 100 microns in diameter → cannot pass through the micropores
- Water vapor molecules are about 0.0004 microns in diameter → pass through freely
Advantages:
- Extremely high MVTR (≥15,000 g)
- Good windproof performance (the microporous structure disrupts airflow)
Disadvantages:
- High cost (ePTFE requires licensed production)
- Micropores can be blocked by oils, sweat, and detergents
4.3 Comparison of the Two Membrane Technologies
| Parameter | Hydrophilic Non‑Porous TPU Membrane | Microporous ePTFE Membrane (Gore‑Tex‑like) |
| Hydrostatic head | 8,000‑15,000 mm | ≥20,000 mm |
| MVTR (inverted cup method) | 5,000‑10,000 g | ≥15,000 g |
| Cost (RMB/m) | 15‑30 | 60‑150 |
| Hand feel | Stiffer | Soft |
| Wash durability | Good (50+ washes) | Fair (requires maintenance) |
| Representative products | Mid‑range tactical softshells | High‑end military/police garments, Gore‑Tex |
5. How to Read Softshell Jacket Product Specifications
5.1 Typical Labels on Product Tags
A qualified tactical softshell jacket typically displays information like this on its label or product page:
- Waterproof & Breathable Performance
- Hydrostatic head: ≥10,000 mm before wash, ≥8,000 mm after 5 washes
- MVTR: ≥8,000 g/m²/24h (JIS L1099 B1 inverted cup method)
- Fabric construction: face fabric (nylon 4-way stretch) + TPU hydrophilic membrane + fleece backer
5.2 Three Key Points to Note
(1) Distinguish between before-wash and after-wash values
Many cheap products only list before‑wash data. After a few washes, performance drops sharply. Qualified products should also list retained values after 5 washes (typically hydrostatic head retention ≥80%).
(2) Confirm the MVTR test method
Different test methods produce vastly different results:
| Test method | Typical value for same sample | Explanation |
| JIS L1099 B1 (inverted cup) | 8,000 g | Closest to real‑world wear, most demanding |
| ASTM E96 (desiccant/water method) | 12,000‑15,000 g | Higher values, often used in marketing |
| ISO 15496 | 10,000‑12,000 g | Middle ground |
The same product might measure 15,000 using ASTM E96 but only 8,000 using JIS B1. Always confirm the test standard when purchasing.
(3) Consider seasonal differences
- Summer softshells: prioritize MVTR (≥8,000 g), hydrostatic head can be slightly lower (8,000 mm)
- Winter softshells: prioritize waterproofness (≥10,000 mm), MVTR can be slightly lower (5,000 g)
6. Waterproof & Breathable Requirements for Different Scenarios
| Use scenario | Recommended hydrostatic head | Recommended MVTR | Explanation |
| Urban commuting, light rain | 5,000‑8,000 mm | 3,000‑5,000 g | Light waterproofing, high breathability not required |
| Tactical training, moderate activity | 8,000‑10,000 mm | 5,000‑8,000 g | Balanced, suitable for most tasks |
| Military/police field duty, heavy rain | 10,000‑15,000 mm | 8,000‑10,000 g | Recommended standard |
| High‑intensity climbing, skiing | 15,000‑20,000 mm | 10,000‑15,000 g | Professional grade |
| Polar regions, extreme altitude | >20,000 mm | >15,000 g | Military grade, Gore‑Tex Pro level |
7. Frequently Asked Questions (FAQ)
A: Yes, but note that softshells typically only have seam taping on main seams, not fully seam-sealed like dedicated rainwear. If you need prolonged exposure to heavy rain, choose a fully seam-taped softshell or a dedicated rain jacket.
A: Theoretically yes, but extremely high MVTR often comes with a thinner membrane and reduced durability. 8,000-10,000 g is the "sweet spot" for tactical softshells, balancing comfort and durability.
A: A factory can use a DIY water column device (transparent tube 1.2 m high). Clamp fabric at the bottom, fill water to 1 meter, and observe for 1 minute. No leakage indicates ≥10,000 mm.
A: Yes. Each wash slightly reduces performance. Recommendations: wash inside out, use mild detergent, never use fabric softener, line dry (do not tumble dry). After 5- 6 washes, use a DWR spray to restore the water-repellent outer layer.
8. Product Description Template (For End Users)
- Tactical Softshell Jacket | Waterproof & Breathable: 10,000 mm Hydrostatic Head / 8,000 g MVTR
- Waterproof: Hydrostatic head ≥10,000 mm - stormproof, remains dry after 2 hours of heavy rain
- Breathable: MVTR ≥8,000 g/m²/24h (inverted cup method) - stays dry during moderate activity
- Fabric: Nylon 4-way stretch face fabric (abrasion-resistant + stretch) + TPU hydrophilic membrane (waterproof/breathable) + fleece backer (warmth)
- Construction: Main seams heat-sealed -no leakage
- Applications: Military/police duty, outdoor hiking, tactical training, daily commuting
Colors: Black, coyote brown, olive green, grey
