The waterproof treatment of elastic fabrics mainly includes three mainstream technical routes: water-repellent (DWR) finishing, composite film waterproofing, and coated fabric waterproofing. These methods differ greatly in air permeability, hand feel, hydrostatic pressure resistance and applicable scenarios, and they are the core basis for functional fabric selection.
Overview of the other waterproof routes:
- Water-repellent finishing — changes surface energy, adds no film and no hydrostatic head
- Composite film waterproofing — a membrane bonded to the back of the fabric
- Coated fabric waterproofing — the surface-film route covered on this page
Coated fabric waterproofing stands out in the textile functional industry with stable performance, wide adaptability and cost-effectiveness. Its core principle is to form a dense waterproof film on the fabric surface through physical film formation or chemical modification, blocking the voids between fibers. Finished coated fabrics generally possess hydrostatic pressure resistance, capable of resisting rain erosion and water immersion. The mainstream industrial processes are dry coating and wet coating, plus a modified mini-wet coating optimized for lightweight elastic fabrics. With industrial upgrading, the application boundaries of each process have become clear. Currently, coated fabrics are gradually phased out of high-end apparel fabrics and mainly applied in outdoor supplies, home textiles and industrial protection fields.
I. How Coated Fabric Waterproofing Works: Dry Coating, Wet Coating and Hydrostatic Head
The core logic of coated fabric waterproofing is “pore sealing, water blocking and controllable moisture permeability”. Polymer coating slurry covers the fabric surface and fills fiber gaps to fundamentally solve water penetration problems. Differences in film formation and solvent treatment divide the technology into two mainstream industrial processes: dry coating and wet coating, whose performance gaps are mainly determined by internal film structure.
1. Dry Coating: Solvent Evaporation, Dense Film
Dry coating is a traditional and simple process without complex phase inversion reaction. The waterproof coating agent and additives are mixed with conventional solvents to prepare uniform slurry, which is evenly scraped or roller-coated on the fabric surface. Subsequent high-temperature drying volatilizes solvents and cures the slurry into a solid, dense waterproof film. This process features short production cycles and high output with uniform coating thickness. The finished fabric has strong film adhesion, excellent wear resistance and aging resistance. Its main disadvantage is the non-porous film structure, resulting in stiff hand feel and poor air permeability.
2. Wet Coating: Phase Inversion, Micro-Pores
Wet coating adopts a solvent phase inversion mechanism to balance waterproof performance and moisture permeability. Polymer materials are dissolved in special organic solvents to make coating slurry. After coating, the fabric is soaked in water for solvent replacement instead of direct high-temperature drying, forming uniform micro-pores inside the coating before final shaping. The micro-porous structure blocks liquid water molecules while discharging gaseous sweat molecules, enabling coated fabrics to achieve reliable waterproof performance and comfortable wearing breathability.
3. Hydrostatic Head: The Number Behind the Word “Waterproof”
Hydrostatic pressure resistance (unit: mmH₂O) is the core index to evaluate the waterproof grade of coated fabrics. It refers to the maximum vertical water pressure a fabric can withstand without water seepage, and higher values represent better waterproof stability. Ordinary water-repellent finishing has no hydrostatic pressure resistance at all — it only makes water bead and roll off the surface. Conventional coated fabrics feature a hydrostatic pressure of 3000–8000 mm, resisting heavy rain scouring. High-end wet-coated and thick dry-coated fabrics can exceed 10000 mm, adapting to high-intensity outdoor waterproof scenarios.
II. Coated vs Laminated vs 4-Way Stretch: Which Route Fits Your Program?
The three routes are not interchangeable, and the difference between them is not a matter of quality — it is a matter of geometry. Coating applies a film on top of the fabric surface. Lamination bonds a membrane to the back of the fabric. Water-repellent finishing changes the surface energy of the fibers and adds nothing on top at all. What separates them commercially is whether the fabric has to stretch.
| Route | How it blocks water | Effect on stretch | Typical hydrostatic head | Usually specified for |
| Water-repellent (DWR) finishing | Lowers fiber surface energy; water beads and rolls off | None — stretch fully preserved | No hydrostatic head; spray rating only (AATCC 22) | Light rain, wind shells, packable layers |
| Coating (dry, wet, mini-wet) | Sealed polymer film or micro-porous film bonded to the face | Warp direction stiffens; tolerable only on low-elastic, lightweight substrates | 3000–12000 mm | Tents, tarpaulins, workwear, industrial and home protection |
| Lamination (2L, 2.5L, 3L) | Membrane bonded to the back; water blocked by the membrane | Retained, provided bonding tension is controlled | 5000–20000+ mm | Outdoor apparel, softshell, stretch shells, performance pant programs |
1. What Coating Does to a Stretch Fabric
A coating is a film laid on top of the fabric. When the fabric elongates, the film does not elongate with it. The first thing to go is the warp direction: the yarn cannot extend because it is locked under a cured polymer layer, so the hand turns papery and the warp elasticity is lost. Even mini-wet coating, the modified process used for lightweight low-elastic nylons, only reduces this constraint — it does not remove it. This is not a process deficiency that a better supplier can engineer away. It is simply what a surface film does to a fabric that is designed to move.
2. Why Lamination Handles Stretch Differently
Lamination starts from the same physics but a different architecture. The membrane is bonded while the base fabric is held flat and under controlled tension, so movement is carried by the weave and the yarn rather than by a film sitting on the surface. Understanding what laminated fabric actually is, and how a two-layer build differs from a three-layer one, is the prerequisite for writing a waterproof spec that survives a stretch program. Note also that the membrane material is usually not the variable that decides final elasticity — PTFE and TPU are closer in stretch behavior than most spec sheets suggest. The bonding tension is what decides it. A line that pulls the fabric longer to gain extra metres locks the warp direction and causes edge curl, the same failure mode as over-stretching in dyeing and finishing.
3. The Decision Rule
If the panel has to move with the wearer — a softshell, a stretch pant, a climbing or ski shell, anything cut from nylon 4-way stretch or polyester 4-way stretch — specify lamination. If the panel is flat and non-deforming where it is used — a tent fly, a tarpaulin, a dust cover, an industrial protection sheet — coating is cheaper and mechanically tougher. Four-way stretch and coating do not belong in the same specification, and a supplier who accepts that combination without flagging it is selling you a complaint.
Our own four-way stretch waterproof programs are therefore routed through our in-house lamination line, where TPU and ePTFE membranes are bonded on site so the peel test, the hydrostatic test and the wash test run under the same roof as the fabric. Where the requirement is stretch without elastane rather than waterproofing, T400 mechanical stretch is the option to compare before the spec is frozen. For the coating processes themselves, the rest of this page covers where they remain the correct answer.
III. Coating on Lightweight Elastic Fabrics: The Mini-Wet Route and Its Limits
Conventional dry and wet coating processes restrict fiber deformation and damage the resilience of elastic fabrics. The industry has developed the improved mini-wet coating process, the optimal waterproof solution for lightweight elastic coated fabrics that balances flexibility, resilience and stable waterproof performance.
The mini-wet coating process simplifies the solvent replacement procedure of traditional wet coating and adopts flexible lightweight coating slurry. The cured high-elastic micro-porous film maximally retains the warp and weft elasticity of the fabric with soft texture, crack resistance and stable hydrostatic pressure, suitable for various low-elastic and lightweight elastic fabrics.
Key note: four-way stretch fabrics rarely adopt coated fabric waterproofing. The bidirectional elastic characteristics of four-way stretch fabrics require high flexibility. Even mini-wet coating will cause slight rigid restraint, resulting in severe loss of warp elasticity and a stiffened texture. Four-way stretch fabrics therefore mainly adopt composite finishing or padding finishing instead of coating technology.
Mini-wet coating is mainly applied to lightweight elastic fabrics including 20D nylon taffeta, 30D twisted nylon four-way stretch fabric, high-elastic polyester pongee and lightweight check fabrics. The finished fabrics achieve a hydrostatic pressure of 1000–2000 mm at ultra-light weight. Practical case: a domestic outdoor brand applies mini-wet coating on 20D lightweight nylon taffeta to manufacture summer outdoor sun protection clothing and lightweight down liner fabrics. The coated fabric maintains stable waterproof performance after 10 washes with original soft elasticity and no stiffening or caking.
IV. Where Coated Fabric Is Still the Right Answer
1. Substrates, Applications and Real Cases
Coated fabrics are applicable to stable, non-deformable non-elastic or low-elastic woven chemical fiber fabrics, mainly including polyester oxford fabric, polyester pongee, taslan, plain nylon fabric and shading chemical fiber fabrics. These substrates feature strong coating adhesion and high waterproof durability.
Currently, coated fabrics have withdrawn from high-end apparel fields and are mainly used in three major scenarios: outdoor supplies, home protection and industrial protection. These scenarios have low requirements for softness and elasticity, perfectly matching the advantages of coated fabrics such as high waterproof performance, excellent wear resistance and high cost performance. Typical cases are as follows:
Outdoor Tent Scenario: 600D polyester oxford fabric with dry PU coating is a universal material for outdoor camping tents. The finished coated fabric achieves a hydrostatic pressure of over 3000 mm, with no water leakage after 2 hours of continuous heavy rain scouring in actual tests. It features excellent tear resistance and outdoor weather resistance with much higher cost performance than composite fabrics.
Protective Raincoat Scenario: Standard protective raincoats adopt thickened polyester dry coated fabrics. Tested under super-typhoon-grade rainfall, the coated fabric maintains stable surface hydrophobicity with a long-term outdoor wear weight loss rate of only 1.7%, suitable for high-intensity outdoor operation and duty protection.
Home and Industrial Protection Scenario: Shading polyester coated fabrics with eco-friendly dry coating are made into household waterproof shading curtains with integrated shading, waterproof and dustproof functions. 300D oxford coated fabrics are widely used in agricultural tarpaulins, equipment dust covers and outdoor luggage fabrics, adapting to humid and dusty complex outdoor environments.
Special Protection Scenario: Military protective fabrics adopt aramid blended base cloth with gradient wet coating. The customized coated fabric realizes low-temperature tear resistance at -40°C, a maximum hydrostatic pressure of 15000 mm and excellent moisture permeability, meeting the extreme requirements of field operation protection.
2. Where the Industry Is Heading
With the iteration of textile functional technology, traditional coated fabric waterproofing has been completely replaced by composite fabric technology in mainstream apparel manufacturing. Traditional coated fabrics have a stiff hand feel, limited air permeability and potential environmental risks, failing to meet the high standards of high-end apparel for skin friendliness, high moisture permeability and environmental harmlessness.
Fabric composite technology forms waterproof and breathable structures through “base fabric + waterproof breathable film” lamination, featuring soft texture, balanced waterproof and moisture permeability, and zero harmful residues, which has become the mainstream choice for outdoor functional apparel. In contrast, coated fabrics are further specialized in non-apparel fields. Driven by environmental upgrading, high-pollution traditional dry and wet coating processes are being phased out, while fluorine-free, low-VOC and water-based coating technologies have become the mainstream development direction of the industry. The same pressure is now visible on the finishing side of waterproofing, where PFAS-free finishing is moving from a brand request to a procurement requirement in the EU.
V. Dry Coating vs Wet Coating: Performance, Environment and Cost
Dry and wet coating processes have significant differences in functionality, environmental performance, cost and applicable scenarios, forming differentiated application ranges for coated fabrics:
1. Functional Comparison
Dry coated fabric: the solid non-porous film provides excellent waterproof tightness with a hydrostatic pressure of 8000–12000 mm, outstanding immersion resistance, wear resistance and aging resistance, and a long service life. The disadvantages are poor air permeability, stiff hand feel and zero tensile toughness, making it completely inapplicable for elastic fabrics.
Wet coated fabric: the micro-porous film structure balances waterproof performance and moisture permeability with a soft and lightweight texture and slight tensile toughness. Conventional hydrostatic pressure ranges from 3000–5000 mm, meeting most daily waterproof needs. The main drawback is weaker scratch and wear resistance; long-term friction and sun exposure will cause micropore blockage and gradual attenuation of waterproof performance.
2. Environmental Performance Comparison
Dry coating process: traditional dry coating consumes a large amount of organic solvents, resulting in high VOC emissions and residual risks with great environmental pressure. The new water-based dry coating improves environmental performance but slightly reduces the waterproof stability of coated fabrics.
Wet coating process: traditional DMF solvent wet coating features high pollution and high post-processing costs. The currently popular fluorine-free and water-based wet coating technologies achieve a high solvent recovery rate, zero harmful residues and low waste emissions, with better overall environmental compliance than dry coating for coated fabrics.
3. Advantages, Disadvantages and Where Each Is Specified
Dry coated fabric: advantages include simple process, high productivity, low cost, excellent waterproof performance and stable quality. Disadvantages are stiff texture, zero air permeability and poor environmental performance of traditional processes. It suits dust covers, industrial tarpaulins, thick waterproof raincoats, shading curtains and other scenarios with low requirements for softness and air permeability.
Wet coated fabric (including mini-wet coating): advantages include soft texture, excellent air permeability and moisture permeability, good environmental performance and adaptability to lightweight low-elastic fabrics. Disadvantages are complex process, high production cost and average wear and aging resistance. It is applied to mid-to-high-end outdoor protective supplies, lightweight waterproof materials and flexible protective fabrics that require both waterproof performance and comfort.
VI. What This Means for Your Next Waterproof Program
Coated fabric waterproofing is a mature and stable functional finishing technology. Dry coating focuses on high waterproof performance, excellent wear resistance and cost efficiency, while wet coating and modified mini-wet coating focus on soft breathability and lightweight elastic fabric adaptation, building a differentiated application system. Verified by practical cases, coated fabrics hold a stable market share in the outdoor, home and industrial protection fields because of their environmental adaptability. With environmental upgrading and refined technological iteration, lightweight, water-based and low-consumption technologies will be the core development direction of coating, forming a long-term complementary pattern with composite fabrics for apparel use.
The practical takeaway: coating is the answer for flat, non-deforming panels, and lamination is the answer for anything that has to move. If your program is a stretch shell or a performance pant, start with the laminated fabric manufacturer page rather than this one, and we will tell you straight away if the build you have in mind cannot hold its hydrostatic head after the wash cycle you have specified.
VII. Coating and Colour Fastness: The Failure Spliced Panels Expose
Coating is a thermal process, and colour problems start there. The paste is not only dried, it is cured, and curing runs hot: on a typical line the fabric sees roughly 150–170 °C for tens of seconds. Polyester is dyed with disperse dyes, the one dye class that can become mobile again inside that window. The dye re-dissolves, migrates toward the fibre surface, and re-deposits where it lands. A roll can pass greige inspection and finished inspection and still come out of coating with less wash fastness than it went in with.
The damage is uneven, which is why sample review often misses it. Dark shades and high-density substrates hold more dye and release more of it; on a single solid colour the loss may be only half a grade. Put that same fabric into a spliced garment — black next to white, red next to white — and the migrated dye turns into visible cross-staining along seams, folds and cut edges, with the light panels picking up colour they were never dyed with. Most brands first see it in a wash test, after the garment has already been cut.
If your substrate is disperse-dyed polyester and coating is the next step, treat colour as a coating-stage property. Specify the fastness grade on coated goods rather than on greige, ask the mill which dye class it uses and how that class tolerates the curing temperature, and keep the cure profile inside what the dye system can take. No cutter can undo the thermal history of a coating line.
We met this failure on a 420T polyester pongee down-jacket programme in black-white, red-white and pink-white splits, where the staining appeared only after coating: the case, and the process change that fixed it.
VIII. Case Study: Why We Turned Down a Coated Fabric Order
Why we declined a 30D nylon four-way stretch coating order.
