Digital Pretreatment Viscosity vs. Application Method: Why the Same Product Behaves Differently in Padding, Coating and Spray Systems

Digital textile pretreatment viscosity is meaningful only when it is connected to the application method. A product that performs well in padding may meter poorly through a coating head, while a coating-grade pretreatment may be too structured or difficult to atomize in a spray system. The reason is that padding, coating and spray expose the formulation to different shear rates, residence times, pressure, extensional deformation, surface-wetting conditions and recovery requirements. Therefore, the same Brookfield viscosity does not guarantee the same application behavior. The correct pretreatment should be selected from viscosity together with rheology, filtration, wetting, fabric pick-up, surface localization, holding stability and final printing performance.

Why Does the Same Pretreatment Behave Differently in Padding, Coating and Spray?

Because the pretreatment is not exposed to the same flow conditions in each machine.

Padding, coating and spray impose different combinations of:

• Shear rate
• دباؤ
• قیام کا وقت
• Extensional deformation
• Surface wetting
• ساختی بحالی

A useful simplified view is:

Padding → Flow + Wetting + Nip Expression

Coating → Metering + Shear + Leveling + Recovery

Spray → Pumping + Nozzle Passage + Atomization + Droplet Deposition

This is why:

Same Product Concentration ≠ Same Application Behavior

اور:

Same Brookfield Viscosity ≠ Same Rheological Performance.

The correct pretreatment should be judged by how it behaves inside the actual application method and on the actual fabric.

Viscosity vs. Rheology: What Is the Difference?

Viscosity describes resistance to flow under a defined test condition.

Rheology describes the broader relationship between:

• Stress
• Shear rate
• وقت
• Structure
• بحالی

Two pretreatments can show the same viscosity at one spindle speed but behave differently when:

• Pumped
• Squeezed through a nip
• Dragged under a coating knife
• Forced through a spray nozzle

Therefore, viscosity should be treated as one rheological data point—not the full application specification.

Why One Brookfield Number Is Not Enough

A Brookfield-type rotational reading is useful for batch control because it is simple and repeatable when the method is fixed.

But the reading depends on:

• توجہ
• درجہ حرارت
• Spindle / rotor
• گردشی رفتار
• پڑھنے کا وقت
• Preparation history

For non-Newtonian pretreatments, changing spindle speed can produce a different apparent viscosity because the polymer structure responds to shear.

Therefore, a supplier statement such as:

“Viscosity = 2,000 mPa·s”

is incomplete unless the test method is known.

A useful pretreatment TDS should define the viscosity test conditions clearly.

Different Application Methods Create Different Shear Conditions

The apparent viscosity that matters in a storage tank is not necessarily the apparent viscosity that matters at the coating blade or spray nozzle.

The route can expose the product to low, medium or high local shear depending on machine geometry and speed.

This means a formulation can:

• Look thick at rest
• Flow easily under application shear
• Recover after deposition

which may be desirable in one route.

Another formulation can:

• Lose structure under shear
• Recover too slowly
• Penetrate or level too far

which may be undesirable.

Application testing should therefore include more than one shear condition whenever process sensitivity is high.

What Padding Requires from Pretreatment Rheology

Padding requires the pretreatment liquor to wet and penetrate the fabric sufficiently before excess liquor is expressed at the nip.

Useful padding behavior generally requires:

• Reliable wetting
• Stable bath viscosity
• Easy circulation
• Low gel / residue
• Consistent wet pick-up

Padding does not normally need the same high surface-holding structure as a knife coating system.

Too much structure can slow wetting or produce unstable pickup, while too little structure can increase penetration or reduce surface localization depending on the fabric.

When Padding Viscosity Is Too Low

A very low-viscosity padding liquor can:

• Penetrate deeply into absorbent fabrics
• Reduce surface localization of polymer
• Increase face-to-back chemical distribution
• Become more sensitive to fabric absorbency differences

This does not automatically mean low viscosity is wrong.

For some dense fabrics, low-viscosity flow may improve uniform wetting.

The relevant test is:

Wet Pick-Up + Dry Add-On + Surface Distribution + Final Print Performance.

When Padding Viscosity Is Too High

Excessive padding viscosity can:

• Slow bath exchange into the fabric
• Create uneven wetting
• Increase sensitivity to roll speed
• Increase foam retention
• Reduce easy circulation / filtration

It may also create a false impression that higher viscosity always improves surface color.

If high viscosity reduces wetting uniformity, final shade can become less stable even if the average surface add-on increases.

What Coating Requires from Pretreatment Rheology

Coating requires the pretreatment to be metered into a controlled layer and then remain sufficiently uniform on the textile until drying.

Useful coating behavior often depends on:

• Viscosity under coating shear
• شیر تھننگ
• سطح بندی
• ساختی بحالی
• Penetration resistance

The coating should flow enough under the blade or metering element to form a uniform film.

After application, it should not continue flowing so freely that it penetrates or redistributes uncontrollably before drying.

When Coating Viscosity Is Too Low

Potential symptoms include:

• زیادہ دخول
• Low surface hold
• Uneven coating weight on absorbent fabrics
• Edge flow / drainage
• Lower surface color concentration after printing

But apparent low viscosity alone does not prove the coating will fail.

A shear-thinning product can show a modest low-shear reading but still provide useful recovery after coating.

Measure actual coating weight and penetration.

When Coating Viscosity Is Too High

Potential symptoms include:

• Poor metering
• Ridges or streaks
• Blade pressure sensitivity
• Insufficient leveling
• Widthwise sensitivity to small gap differences

High viscosity can also increase the force required to move the formulation beneath the coating head.

A product that looks “stable” in the beaker can therefore create an uneven surface layer in production.

What Spray Requires from Pretreatment Rheology

Spray adds another requirement: atomization.

The liquid must:

• Pump reliably
• Pass through filters
• Pass through the nozzle
• Break into droplets
• Deposit uniformly
• Wet the fabric without excessive bounce or runoff

This means spray suitability depends on more than rotational viscosity.

High polymer elasticity, stringiness, gel particles or unstable filtration can all cause problems even when the measured viscosity seems acceptable.

When Spray Viscosity Is Too Low

A very low-viscosity spray liquid may atomize easily, but it can also:

• Produce very fine droplets depending on nozzle conditions
• Increase mist / overspray
• Penetrate rapidly into absorbent fabric
• Reduce face localization

The nozzle, pressure and flow rate matter.

Do not optimize spray solely by making the pretreatment as thin as possible.

When Spray Viscosity Is Too High

Higher viscosity can create:

• Larger droplets
• Poor atomization
• Uneven spray pattern
• Higher nozzle-pressure demand
• Nozzle / filter blockage risk

Polymer-rich formulations can also show filament formation or stringing during breakup.

Therefore, spray qualification should include:

• Nozzle pattern
• Droplet behavior
• Widthwise deposition
• چھانٹائی

not only viscosity.

Shear Thinning: Why It Matters

Many polymeric textile pretreatments are shear-thinning.

This means apparent viscosity decreases as shear rate increases.

Shear thinning can be useful because the product can:

• Remain structured at rest
• Flow under pumping / application
• Recover after deposition

But the ideal degree of shear thinning differs by route.

Padding generally prioritizes wetting and pickup stability.

Coating often benefits from a stronger balance between flow under blade shear and post-application recovery.

Spray needs enough flow through the nozzle and predictable atomization.

Yield Stress and Structure at Rest

Some pretreatments behave as if a minimum stress must be applied before they flow significantly.

This structural resistance can help:

• Reduce settling
• Hold chemistry near the fabric surface
• Reduce uncontrolled drainage

But excessive structure can create:

• Poor pumpability
• Coating ridges
• Spray instability

Yield-like behavior can therefore be helpful in coating but problematic in spray if it is too strong.

Do not infer yield behavior from a single low-speed viscosity value alone.

Structural Recovery and Thixotropy

Thixotropic systems lose structure under shear and recover over time after shear is removed.

The recovery rate matters because:

• Too-slow recovery can allow coating to penetrate or spread after application.
• Too-fast recovery can reduce leveling and create ridges or streaks.
• In padding, excessive time dependence can cause bath behavior to change with circulation history.
• In spray, recovery after atomization affects droplet spreading on the fabric.

A product with identical initial Brookfield viscosity can therefore behave differently if structural recovery is different.

Extensional Behavior and Spray Atomization

Spray breakup is not governed only by shear viscosity.

As liquid leaves a nozzle, it stretches and breaks into droplets.

Polymer solutions can resist this stretching differently from simple Newtonian liquids.

High extensional resistance can lead to:

• Longer liquid filaments
• Stringing
• Larger or less uniform droplets

This is one reason two pretreatments with similar rotational viscosity can atomize differently.

For spray applications, direct nozzle trials are essential.

Surface Tension and Wetting

Rheology controls flow, but wetting controls how the applied liquid interacts with the fabric surface.

Poor wetting can cause:

• Beading
• Patchy spray deposition
• Poor coating continuity
• Slow padding penetration

Excessive wetting can cause:

• Too much penetration
• Loss of surface localization
• Higher bleeding risk later

The correct viscosity must therefore be matched with appropriate wetting behavior.

Filtration, Gel and Particle Control

Digital pretreatment is normally applied to the fabric rather than jetted through the printhead, but filtration still matters.

The product can pass through:

• Mixers
• Pumps
• Filters
• Coating heads
• Spray nozzles

Gel particles or incomplete hydration can:

• Block spray nozzles
• Create coating streaks
• Deposit unevenly during padding

Use a standardized filtration test with the same sample mass, filter opening and holding time.

Holding Stability Before Application

A pretreatment can meet its viscosity target immediately after preparation but drift during production holding.

Possible changes include:

• Viscosity increase
• Viscosity decrease
• علیحدگی
• جیل کی تشکیل
• جھاگ

This can affect each route differently.

Padding may show pickup drift.

Coating may show coating-weight or leveling drift.

Spray may show nozzle-pattern drift.

Evaluate viscosity and application behavior over the real production holding period.

Temperature Sensitivity

Viscosity depends strongly on temperature.

A pretreatment measured at laboratory temperature can become noticeably thinner in a warm production area or warm circulation loop.

Temperature variation can therefore change:

• Padding pickup
• Coating weight
• Spray atomization

Always record temperature with the viscosity result.

For production comparison, measure samples at the same controlled temperature or record the actual process temperature.

Electrolytes, pH and Water Quality

Reactive digital pretreatments can contain:

• الکلی
• یوریا
• نمک
• Hard-water ions

These can change polymer hydration and rheology.

The same product can therefore show different viscosity when prepared in:

• Different plant water
• Different alkali system
• Different auxiliary package

For sensitive systems, record:

• پانی کی سختی
• Conductivity
• پی ایچ

together with viscosity.

Fabric Structure Changes the Viscosity Window

The optimum pretreatment viscosity depends on the textile.

A highly absorbent fabric can pull low-viscosity liquor into the structure quickly.

A dense fabric can require easier flow to achieve uniform wetting.

A stretch knit can be sensitive to mechanical tension in coating or padding.

Therefore, application viscosity should always be validated on the actual:

• Fiber
• تعمیر
• جی ایس ایم
• موٹائی
• جذب کرنے کی صلاحیت

کپاس

Cotton can be treated by padding, coating or spray depending on construction and target.

Absorbent cotton may allow rapid penetration of lower-viscosity pretreatment.

For cotton, compare:

• Face-side add-on
• Back-side penetration
• Post-wash K/S
• Bleeding

rather than selecting viscosity from fiber name alone.

Viscose / Modal

Viscose and modal generally show high swelling and water uptake.

This can make low-viscosity padding liquor penetrate deeply and can make coating or spray rapidly absorb into the fabric.

The useful viscosity window may therefore differ from cotton even when the same reactive ink and pretreatment product are used.

Control:

• Wet pick-up
• Dry add-on
• دراندازی
• Residual moisture

Lyocell

Lyocell is regenerated cellulose but should not be treated as identical to viscose.

Fabric construction, fibrillation control and finishing history can change wetting and penetration.

Route-specific viscosity should be qualified on the actual lyocell fabric.

Woven vs. Knit

Woven fabrics are generally dimensionally more stable under coating gap and padding pressure.

Knits can change width and thickness under tension, which changes effective coating geometry and wet pickup.

لہٰذا:

• Padding viscosity on a knit should be evaluated together with tension and width stability.
• Coating rheology should be evaluated together with fabric deflection and thickness.
• Spray rheology should be evaluated together with fabric support and motion.

Viscosity vs. Wet Pick-Up / Coating Add-On / Spray Add-On

Viscosity should not be optimized without measuring actual application output.

روٹ	Primary Application Output
Padding	Wet pick-up
Coating	Wet / dry coating weight
Spray	Deposited wet add-on / dry active add-on

For each route, compare:

Viscosity / Rheology → Application Add-On → Dry Add-On → Print Result

This prevents the mill from optimizing a beaker measurement that does not improve the fabric.

Viscosity and Pretreatment Penetration

Lower viscosity often promotes easier liquid movement, but penetration is not controlled by viscosity alone.

Also important are:

• Fabric porosity
• Surface tension
• Application pressure
• Contact time
• Polymer–fiber interaction

Higher viscosity can reduce penetration in some systems, but excessive viscosity can also create poor surface uniformity.

The correct objective is:

Controlled Penetration, Not Maximum Viscosity.

Viscosity, Water Load and Drying

Changing viscosity often changes how much liquid the route applies or how deeply it penetrates.

This can change:

• Water load
• Drying rate
• Chemical migration
• Residual moisture

For example, a lower-viscosity padding liquor can increase penetration but not necessarily wet pick-up.

A coating with higher surface hold can reduce deep water movement but may leave a concentrated surface film.

A spray route can use less carrier water but still require the same dry active add-on.

Revalidate dryer settings after significant rheology changes.

How Application Rheology Changes Ink Spreading and Color Yield

The pretreatment layer determines how the later inkjet droplet behaves.

If pretreatment rheology produces poor application uniformity, digital printing can show:

• Bleeding
• Line-width variation
• نامتناسب ٹھوس علاقے
• Color-depth differences

A more surface-localized pretreatment can increase apparent face color if fixation remains adequate.

A deeply penetrating pretreatment can reduce surface polymer concentration and allow more ink penetration.

Therefore, evaluate:

• باریک لکیر کی تعریف
• دراندازی
• Post-wash K/S

together.

How It Changes Reactive Fixation

For reactive printing, pretreatment carries fixation chemistry such as alkali and moisture-management components.

If rheology changes application add-on or penetration, it can also change:

• Alkali add-on
• نمی کی تقسیم
• Steaming response

A viscosity change that appears to be only a mechanical issue can therefore become a fixation issue after steaming.

Compare post-wash color and fastness before approving a rheology change.

Why Two Products with the Same Viscosity Can Print Differently

Equal apparent viscosity at one test point does not mean equal:

• Shear-thinning behavior
• Yield structure
• Thixotropic recovery
• Extensional behavior
• Wetting
• پانی کا جمع ہونا
• الیکٹرولائٹ برداشت
• چھانٹائی

This explains a common mill observation:

Product A = 2,000 mPa·s

Product B = 2,000 mPa·s

but:

Application and Print Performance Are Different.

The correct comparison must include the actual machine and fabric.

Padding vs. Coating vs. Spray Rheology Comparison

جائزہ کا شعبہ	Padding	Coating	Spray
Primary flow requirement	Wetting / circulation / nip expression	Metering / leveling / recovery	Pumping / atomization / deposition
Low-shear structure	Moderate control useful	Often important for surface hold	Must not prevent pumping or nozzle flow
شیر تھننگ	Useful if wetting remains stable	Often very useful	Can help nozzle flow but atomization must be verified
بحالی	Bath stability / pickup consistency	Critical for leveling vs. penetration balance	Influences droplet behavior after deposition
Extensional behavior	Less dominant	Secondary	Important for stringing / breakup
Filtration sensitivity	Moderate to high	High for streak prevention	Very high for nozzle reliability
Primary measured output	Wet pick-up	Coating weight	Deposited spray add-on / width profile

This table is a process guide, not a universal viscosity specification.

Build a Useful Viscosity Test Method

A good internal QC method should record:

• Sample concentration
• پانی کا معیار
• Preparation time / hydration time
• درجہ حرارت
• آلہ
• Spindle / rotor
• گردشی رفتار
• پڑھنے کا وقت

Use the same method for:

• Incoming batch QC
• Laboratory matching
• Production troubleshooting

If two products are compared under different methods, the viscosity numbers are not directly meaningful.

Build a Multi-Speed Shear Ladder

When one viscosity value does not explain production behavior, measure apparent viscosity at several rotational speeds using a consistent method.

مثال کے طور پر:

• Low speed
• Reference speed
• Higher speed

Then compare the shape of the response.

This helps distinguish:

• More shear-thinning systems
• Less shear-sensitive systems
• Time-dependent drift

Do not assign one universal “best” PVI or shear ratio across all pretreatment routes.

The useful profile depends on padding, coating or spray requirements.

Build an Application-Method Matrix

Candidate	Padding	Coating	Spray
Current pretreatment	Reference	Trial if relevant	Trial if relevant
Lower-structure candidate	Evaluate wetting / pickup	Evaluate penetration	Evaluate atomization
Higher-structure candidate	Evaluate pickup stability	Evaluate metering / recovery	Evaluate nozzle / stringing risk

For every route, record:

• Application uniformity
• Actual add-on
• سکھانا
• Final printing result

The best product is the one that performs correctly in the intended route—not the one with the highest viscosity.

Laboratory-to-Production Scale-Up

Small laboratory tools do not reproduce all production shear and geometry.

During scale-up, recheck:

• Pump and circulation behavior
• Full-width pickup / coating / spray uniformity
• Line speed
• درجہ حرارت
• وقت پکڑنا
• سکھانا
• Residual moisture

For coating, production gap and web tension become more important.

For spray, nozzle overlap and full-width deposition become more important.

For padding, full-width nip uniformity and bath circulation become more important.

Scale-up should reproduce the fabric condition and print result, not merely the laboratory viscosity.

Common Viscosity-Matching Mistakes

1. Choosing Pretreatment by One Viscosity Number

One apparent viscosity point does not describe full rheology.

2. Using the Same Viscosity Target for Padding, Coating and Spray

Each route creates different flow and shear conditions.

3. Assuming Higher Viscosity Always Improves Sharpness

Excessive structure can reduce wetting, leveling or atomization.

4. Assuming Lower Viscosity Is Always Better for Spray

Very low viscosity can increase misting or penetration and does not guarantee uniform deposition.

5. Ignoring Filtration

Gel particles can create nozzle blockage, coating streaks and uneven application.

6. Ignoring Temperature

Viscosity can change significantly between lab and production temperature.

7. Comparing Products with Different Test Methods

Viscosity values are meaningful only when the test conditions match.

8. Stopping at Application Instead of Printing

The final test is post-wash print quality, not whether the pretreatment looked good in the machine.

حل مسائل کی جدول

مشاہدہ شدہ مسئلہ	چیک کرنے کے لیے اولین متغیرات	فرض نہ کریں
Padding pickup varies despite stable bath concentration	Viscosity, temperature, nip, fabric absorbency	The formula concentration is the only cause
Coating shows ridges / streaks	Shear response, recovery, gap, blade condition	Higher viscosity will fix it
Coating penetrates too deeply	Low-shear structure, wetting, fabric absorbency, add-on	Only solids content matters
Spray creates large uneven droplets	Viscosity, nozzle, pressure, extensional behavior	More pressure alone solves atomization
Spray nozzle blocks	Filtration, gel, hydration, viscosity	The product is too viscous only
Same Brookfield viscosity gives different print result	Shear thinning, recovery, wetting, add-on, penetration	The products are rheologically equivalent
Production viscosity is lower than lab	Temperature, holding, shear history	The polymer batch degraded
Good application but weak post-wash color	Alkali add-on, penetration, residual moisture, fixation	Application viscosity alone defines print quality

استعمال میں کل لاگت

The cheapest pretreatment per kilogram is not necessarily the lowest-cost application system.

ایک مفید ماڈل یہ ہے:

Total Cost in Use = Pretreatment + Preparation + Pumping / Filtration + Application Losses + Drying + Ink + Fixation + Rework + Quality Loss

A product with slightly higher unit cost can be commercially better if it:

• Applies more uniformly
• Reduces nozzle / filter maintenance
• Improves coating consistency
• Reduces pickup drift
• Improves first-pass print quality

Compare cost per acceptable printed meter, not viscosity per dollar or product price per kilogram.

آپ کو سپلائر کو کون سی معلومات بھیجنی چاہئیں؟

For useful viscosity/application matching, provide:

• سیاہی کا نظام
• Fabric fiber / blend
• بُنا ہوا یا وُنا ہوا
• جی ایس ایم / موٹائی
• Current pretreatment product / TDS
• Current viscosity and full test method
• Application method: padding / coating / spray
• Wet pick-up or coating / spray add-on
• Application equipment details
• Line speed
• Water hardness / conductivity where relevant
• Pretreatment pH / electrolyte system
• خشک کرنے کے حالات
• Main issue: pickup, streaking, penetration, atomization, bleeding or weak color

FSX کیمیکل اس معلومات کو کے ذریعے استعمال کر سکتا ہے۔ نمونے اور ملاپ to compare rheology and application fit rather than matching only one viscosity number.

نظرثانی Digital Textile Printing Pretreatment اور Textile Printing Applications for related process selection.

How Should a Mill Match Pretreatment Viscosity to the Application Method?

A practical workflow is:

Define Fabric + Application Route → Standardize Viscosity Method → Measure Multi-Speed Response if Needed → Check Filtration / Holding → Apply at Controlled Add-On → Dry → Print → Fix → Wash → Compare Final Performance

اہم اصول یہ ہیں:

1. Viscosity is a test result; rheology is the broader flow behavior that controls application.
2. Padding, coating and spray require different balances of wetting, shear thinning, recovery and flow.
3. Same Brookfield viscosity does not mean the same application performance.
4. Application output—wet pick-up, coating weight or spray add-on—must be measured together with viscosity.
5. Fabric structure and water/electrolyte conditions can shift the useful viscosity window.
6. The best pretreatment is the product whose rheology remains stable in the intended application route and delivers the required post-wash digital-print quality at the lowest practical Total Cost in Use.

اکثر پوچھے جانے والے سوالات

1. Can the same pretreatment viscosity be used for padding, coating and spray?

Not automatically. Each application method creates different shear, pressure, wetting and recovery requirements, so the useful viscosity window can differ.

2. Why do two products with the same Brookfield viscosity behave differently?

They can differ in shear thinning, yield structure, recovery, extensional behavior, wetting, filtration and electrolyte tolerance.

3. Is higher viscosity better for padding?

Not always. Excessive viscosity can reduce wetting and bath exchange, while very low viscosity can increase penetration. Measure actual wet pick-up and print performance.

4. Is higher viscosity better for coating?

Only within a useful rheological window. Too little structure can cause penetration and flow; too much can cause poor metering, ridges and poor leveling.

5. Does spray require the lowest viscosity?

No. Spray requires reliable pumping and atomization, but very low viscosity can increase misting or penetration. The nozzle and formulation must be matched together.

6. Why does spray string or form large droplets?

High viscosity, polymer elasticity, extensional resistance, nozzle geometry or pressure can contribute. Direct nozzle testing is necessary.

7. Why is filtration important for fabric pretreatment?

Gel and incompletely hydrated particles can block spray nozzles, create coating streaks or cause uneven application even though the pretreatment is not printed through an inkjet head.

8. Should viscosity always be measured at one speed?

A single speed is useful for routine QC, but multi-speed measurements can help explain shear-thinning differences when products with similar reference viscosity behave differently.

9. Why does production viscosity differ from laboratory viscosity?

Temperature, water quality, holding time, shear history, concentration and mixing can all change apparent viscosity.

10. How does fabric type affect the useful viscosity?

Absorbency, thickness, porosity and stretch determine how quickly pretreatment penetrates and how application geometry behaves.

11. Should I match a competitor product only by viscosity?

No. Match viscosity method, rheology, filtration, add-on, drying and final printing performance. Same viscosity alone does not prove equivalent behavior.

12. What should I send FSX Chemical for viscosity matching?

Send the current TDS or sample, full viscosity test method, application route, fabric, wet/dry add-on, line speed, water/pH conditions and the exact application or printing problem.

Match Pretreatment Rheology to the Machine, Not Just the Viscosity Number

If a digital pretreatment performs well in one machine but becomes unstable in padding, coating or spray, FSX Chemical can help compare the current product by viscosity method, rheology, filtration, application add-on and final printing result.

کے ساتھ شروع کریں نمونے اور ملاپ and provide your current pretreatment, fabric, viscosity test conditions and application route.

نظرثانی Digital Textile Printing Pretreatment for the current FSX pretreatment routes📧 ای میل: Service@fsxchemical.com

The correct viscosity is not the highest, lowest or most familiar laboratory number. It is the rheological window that allows the pretreatment to move correctly through the intended application equipment, deposit uniformly on the actual fabric, survive drying and fixation, and deliver stable post-wash color and definition.