Kaolin Clay Grade Selection Guide: How to Choose the Right Grade from a Kaolin Clay Supplier in India
Choosing a kaolin grade is not about finding the "best" kaolin — it is about matching the right whiteness, chemistry, particle size, and consistency to what your end product needs. Buy a grade that is too low and your tiles, coatings, or compounds miss their colour target. Buy a grade that is higher than necessary and youpay for whiteness your formulation never uses.
This guide is written by the quality team at Pacific Minerals, a mine-owning manufacturer, exporter, and kaolin clay supplier in India based in Dhaneti, Bhuj-Kutch, Gujarat. It explains the six parameters that define a kaolin clay grade, how to read an L value correctly, which grade to start with for tiles, paints, adhesives, rubber, and paper, and exactly what to ask any supplier before you place a bulk order.
The Short Answer: Which Kaolin Grade Do You Need?
For most industrial buyers, the decision comes down to how visible whiteness is in the finished product. Where colour is critical — white-body wall tiles, engobes, light-coloured coatings, and paper — start with a high-whiteness L94+ grade. Where kaolin is used in coloured, tinted, or pigmented products, or where cost per tonne matters more than the last point of whiteness, an L93 grade is usually the more economical starting point. In every case, confirm the choice with a sample trial in your own formulation.
Whiteness is only one parameter. Two kaolins with the same L value can behave very differently in a tile body or a paint because their iron and titanium content, particle size, and moisture differ. The rest of this guide explains how to evaluate all of them.
What Is Kaolin Clay (China Clay)?
Kaolin clay, also called china clay, is a naturally occurring white clay made mostly of the mineral kaolinite, a hydrous aluminium silicate with the formula Al₂Si₂O₅(OH)₄. The names are interchangeable: "kaolin" comes from Gaoling (Kao-ling), the hill near Jingdezhen in China where the clay was first mined for porcelain, and "china clay" refers to the same material.
Industries use kaolin because it is white, chemically inert, fine-grained, and relatively low-cost. It acts as a whitening and alumina source in ceramics, an extender and filler in paints and coatings, a filler in adhesives and sealants, a non-black filler in rubber, and a filler that improves opacity and printability in paper. For a full overview of our production, see our main kaolin clay page.
The 6 Parameters That Define a Kaolin Clay Grade
A kaolin clay grade is defined by six measurable parameters: whiteness (L value), iron and titanium content, particle size distribution, residue or grit, moisture content, and application behaviour such as plasticity or viscosity. Grade names from different suppliers are not standardised, so always compare these parameters rather than the grade label.
1. Whiteness (L Value)
Whiteness is the most visible parameter and the one most buyers ask about first. It is typically reported as an L value — the lightness coordinate on the CIELAB colour scale. Higher numbers mean a whiter, brighter-looking powder. Pacific Minerals supplies high-whiteness kaolin in two grades: L Value 93 and L Value 94+, measured batch-wise in our QC process.
2. Iron Oxide (Fe₂O₃) and Titanium Dioxide (TiO₂) Content
Iron and titanium are the main colouring impurities in kaolin. They reduce raw whiteness and, in ceramics, they can darken or yellow the fired body even when the raw powder looks white. If your product is fired, ask for Fe₂O₃ and TiO₂ values on the certificate of analysis, not just the raw L value.
3. Alumina (Al₂O₃) and Overall Chemistry
Pure kaolinite contains roughly 39.5% Al₂O₃, 46.5% SiO₂, and 14% combined water. Real kaolin deposits contain some free quartz and other minerals, so alumina is lower. Higher alumina generally indicates a purer kaolin and matters in ceramics, where alumina affects the firing behaviour and strength of the body.
4. Particle Size Distribution (PSD)
Particle size affects how kaolin disperses, how smooth the final surface is, how much it reinforces a rubber compound, and how it influences viscosity in paint and adhesives. Finer kaolin generally gives smoother surfaces and better suspension; coarser kaolin is often easier to handle and lower in cost. Ask for PSD as a percentage below a stated size (for example, % below 2 microns) along with the test method.
5. Residue on Sieve (Grit)
Residue measures coarse particles — often quartz or unrefined grains — left on a fine sieve after wet sieving, commonly a 325 mesh (45 micron) screen. Grit causes surface defects in coatings, specks in paper, abrasion in processing equipment, and weak points in rubber. For surface-critical applications, specify a maximum residue in your purchase contract.
6. Moisture Content and Application Behaviour
Moisture affects how the powder flows, how accurately it doses, how it stores, and how much water you pay freight on. It is checked on every batch in our QC process. Beyond moisture, each industry has its own behaviour test — plasticity and dry strength for ceramics, oil absorption and viscosity for paints, and dispersion behaviour for adhesives. Ask your supplier which of these they can test, and run your own trial.
Understanding L Value: Why Whiteness and Brightness Are Not the Same Number
L value (CIELAB L) is a lightness scale running from 0 (black) to 100 (perfect white). It is not the same measurement as ISO brightness, which the paper industry uses, or as a whiteness index. A kaolin reported as "L 94" and another reported as "94 brightness" cannot be compared directly — they are measured differently.
This is one of the most common sources of confusion when buyers compare quotations from different suppliers:
• L value (CIELAB L) measures overall lightness across the visible spectrum. It is widely used for ceramics, coatings, and filler-grade kaoli
• ISO brightness measures reflectance of blue light at a wavelength of 457 nm. It is the standard in paper and pulp and is sensitive to yellowness.
• Whiteness indices (such as CIE whiteness) combine lightness and tint into a single number designed to match how humans perceive "white".
Even the same scale can give different results depending on sample preparation (loose powder or pressed pellet), the instrument, and the light source used. When you compare suppliers, ask three questions: which scale, which instrument, and how was the sample prepared? At Pacific Minerals, every batch is checked for whiteness (L value), and each shipment is supported by a lab test report so you can compare like with like.
Pacific Minerals Kaolin Clay Grades at a Glance
Pacific Minerals supplies two high-whiteness kaolin clay grades from its operations in Kutch, Gujarat: L Value 93 and L Value 94+. Both are suited to tiles, coatings, adhesives, rubber, and paper; the choice between them depends on how critical whiteness is in your finished product and your target cost per tonne.
The applications listed are typical starting points, not guarantees. Final grade selection should always be confirmed with a sample trial in your own process.
Kaolin Clay Grade Selection by Application
The right kaolin grade depends on your application. Ceramic tiles need low iron and good fired whiteness; paints need controlled particle size and low grit; rubber needs low moisture and low grit; paper needs high whiteness and fine particles; adhesives need consistent particle size for predictable viscosity. Here is how to approach each one.
Kaolin for Ceramic Tiles
In tile manufacturing, kaolin contributes alumina and whiteness to the body and helps glazes and engobes stay in suspension. What matters most is fired colour, not just raw whiteness — iron and titanium that are invisible in the powder can show up after firing.
• White-body wall tiles, engobes, and double-charge vitrified tiles: start with L94+, where the body colour is visible or sets the base for the design.
• Glazed floor tiles and coloured bodies: L93 is often sufficient, since the glaze covers the body and cost efficiency matters at high volumes.
• Verify: fired whiteness at your kiln temperature, Fe₂O₃ + TiO₂, plasticity alongside your ball clay, and shrinkage.
Many tile makers also buy silica sand from the same source to simplify logistics — see our silica sand grades for ceramics.
Kaolin for Paints and Coatings
In paints, kaolin works as an extender pigment. It helps space out titanium dioxide, improves suspension, adjusts sheen, and reduces formulation cost.
• Interior whites and pastel shades: start with L94+ to avoid dulling the base colour.
• Deep tints, primers, textured coatings, and industrial coatings: L93 usually performs well at a lower cost.
• Verify: residue/grit (surface defects), oil absorption, effect on viscosity, and dispersion in your grind stage.
Kaolin for Adhesives and Sealants
In adhesives, sealants, and tile adhesives, kaolin is used as a functional filler to build body, control flow, and reduce cost. Consistency from batch to batch matters more than peak whiteness, because a shift in particle size or moisture changes viscosity on your production line.
• Most adhesive and sealant formulations: L93 is a practical starting point.
• White or clear-finish products where colour is visible: consider L94+.
• Verify: moisture (critical for moisture-cured systems), particle size consistency, and viscosity build in your formulation.
Kaolin for Rubber
In rubber compounding, kaolin is a non-black filler used to add stiffness, improve processing, and reduce compound cost in products such as footwear soles, hoses, mats, and technical goods.
• Pigmented or dark rubber compounds: L93 is typically adequate.
• White and light-coloured rubber goods: start with L94+.
• Verify: moisture (affects cure), residue/grit (creates weak points), and trace copper and manganese — metals that can accelerate ageing of rubber.
Kaolin for Paper
In paper, kaolin is used as a filler to improve opacity, smoothness, and printability, and — in finer, higher-brightness grades — as a coating pigment. Paper mills measure ISO brightness, so ask for that value alongside L value.
• Filler applications: start with L94+, as whiteness directly affects sheet appearance.
• Coating applications: coating grades require very fine particle size and high brightness. Share your ISO brightness and particle-size targets so we can confirm whether a Pacific Minerals grade fits before you trial.
• Verify: ISO brightness, residue (specks), particle size, and retention in your wet end.
Other Applications
If your application is not listed — or if you need a grade tuned between the standard specifications — tell us your end product and the parameters that matter to you. Custom grades are available as part of our long-term supply approach.
Kaolin Grade Selection Matrix
Use this matrix as a quick reference: find your application, note the parameters that matter most, and start your sample trial with the suggested grade.
Application | Most critical parameters | Suggested starting grade |
White-body wall tiles / engobes | Fired whiteness, Fe₂O₃ + TiO₂, plasticity | L94+ |
Glazed floor tile bodies | Consistency, cost, shrinkage | L93 |
Light-coloured paints | Whiteness, grit, oil absorption | L94+ |
Tinted / industrial coatings | Grit, dispersion, cost | L93 |
Adhesives & sealants | Moisture, PSD consistency, viscosity | L93 (L94+ for white finishes) |
Dark / pigmented rubber | Moisture, grit, Cu/Mn | L93 |
White / light rubber goods | Whiteness, moisture, grit | L94+ |
Paper filler | ISO brightness, residue, PSD | L94+ (confirm by trial) |
How to Select and Qualify a Kaolin Grade: 7 Steps
Qualifying a kaolin grade takes seven steps: define your end-product requirement, identify critical parameters, request a data sheet, test a sample, run a production trial, lock the specification into your contract, and verify every batch with a lab report.
1. Define the end-product requirement. What colour, surface finish, strength, or cost target must the finished product meet?
2. Identify your critical parameters. Use the matrix above. Most buyers need three or four parameters, not all six.
3. Request a technical data sheet and sample lab report. Confirm the test methods behind each number, especially for whiteness.
4. Test the sample in your own lab. Compare it against your current kaolin in the same formulation, under the same conditions.
5. Run a pilot or production trial. Lab results do not always carry over to full-scale kilns, mills, or mixers.
6. Lock the specification in your contract. Agree target values and tolerance bands for each critical parameter.
7. Verify every batch. Require a lab test report with each shipment and spot-check incoming lots against the agreed specification.
6 Common Mistakes Buyers Make When Choosing a Kaolin Grade
1. Buying on whiteness alone. Two kaolins with the same L value can fire to different colours or change your paint viscosity.
2. Comparing L value with ISO brightness. They are different scales. Always ask which scale was used.
3. Ignoring fired colour in ceramics. Raw whiteness does not guarantee fired whiteness; iron and titanium do the damage in the kiln.
4. Not specifying test methods. Without an agreed method, a supplier's "94" and your lab's "92" can both be correct.
5. Overlooking moisture. Excess moisture affects dosing and flow — and you pay freight on the water.
6. Approving one sample, then never checking consistency. Qualification is only as good as the next 50 shipments. Consistency is what a long-term supplier should be judged on.
What to Ask a Kaolin Clay Supplier in India Before You Order
Before you choose a kaolin clay supplier in India, confirm that they control their own raw material, test every batch, provide a lab report with each shipment, can hold your specification over time, and can move material to your port reliably. The checklist below covers the questions experienced buyers ask.
• Do you own or directly operate the mine, or do you trade material from third parties?
• Which parameters do you test on every batch, and which only on request?
• Which scale and method do you use for whiteness?
• Will every shipment come with a lab test report?
• Can you hold a custom specification with agreed tolerances under a supply contract?
• What is your minimum order quantity and standard lead time?
• How far is your plant from the export port, and which ports do you use?
• What packaging options do you offer, and how do you prevent moisture pickup in transit?
• Can you supply annual volume commitments with a planned dispatch cycle?
• Who is my technical contact if a batch does not perform?
To see how Pacific Minerals answers each of these, visit our kaolin clay supplier in India page or contact our team directly.
Why Buyers Source Kaolin Clay from Pacific Minerals
Pacific Minerals combines direct access to kaolin deposits in Kutch, Gujarat, with a semi-automated 24×7 production facility, a structured batch-wise QA process, and a plant located less than two hours from Mundra and Kandla ports. That combination is what keeps grade quality consistent from one shipment to the next.
• Active mining site: direct access to mineral-rich deposits supports consistent quality, supply assurance, and cost efficiency.
• 24×7 semi-automated production: multi-stage washing, refined screening and grading, and large-scale stockyard facilities.
• Batch-wise quality assurance: sieve analysis, moisture content check, whiteness (L value) measurement, impurity screening, load verification, and pre-dispatch inspection — part of our batch-wise quality control process.
• Lab test report with every shipment for confidence and traceability.
• Port proximity: less than two hours from Mundra and Kandla ports for fast outbound logistics.
• Long-term partnership approach: custom grades, supply contracts, annual volume commitments, and reliable dispatch cycles.
“A buyer should never have to guess whether this month's kaolin will behave like last month's. We measure whiteness and moisture on every batch and send the lab report with every shipment, so the grade you approve is the grade you receive.”
Packaging, Documentation, and Export
Pacific Minerals supplies kaolin clay to buyers across India and exports internationally through Mundra and Kandla ports. Kaolin is classified under HS code 2507 (kaolin and other kaolinic clays). Each shipment is supported by a lab test report.
• Packaging options: jumbo bag (with and without pallets), 25kg or 50kg bags, custom packing
• Minimum order quantity: 28MT
• Export documentation: see our export documentation and HS codes guide
The Team Behind Every Grade
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Jadeja Anirudhsinh, Founder & Director — sets the long-term direction of Pacific Minerals and builds lasting relationships with industrial buyers worldwide.
Jadeja Prashantsinh, Operations & Supply Chain Head — manages end-to-end operations, logistics, and delivery so every order ships on schedule.
Jadeja Bharatsinh, Director of QC & Product Development — leads testing and grade development, ensuring every batch meets client specifications.
Jadeja Shanirajsinh, Director of Mining Operations — oversees mining activities with a focus on efficient resource use, safety, and regulatory compliance.
Kaolin Clay Grade Selection: Frequently Asked Questions
What grade of kaolin clay is used for ceramic tiles?
For white-body wall tiles, engobes, and double-charge vitrified tiles, a high-whiteness grade such as L94+ is the usual starting point. For glazed floor tiles and coloured bodies, an L93 grade is often sufficient. Always confirm fired whiteness at your own kiln temperature with a sample trial.
What is L value in kaolin clay?
L value is the lightness coordinate (L*) on the CIELAB colour scale, which runs from 0 (black) to 100 (perfect white). A higher L value means a whiter-looking kaolin. Pacific Minerals supplies kaolin grades with L Value 93 and L Value 94+.
Is kaolin L value the same as ISO brightness?
No. L value measures overall lightness, while ISO brightness measures reflectance of blue light at 457 nm and is used mainly in the paper industry. The two numbers are not directly comparable, so always ask a supplier which scale and method they used.
What is the difference between L93 and L94+ kaolin?
L94+ kaolin is whiter and is preferred where colour is visible in the finished product, such as white wall tiles, light paints, and paper. L93 kaolin offers strong whiteness at a lower cost and suits coloured, tinted, or pigmented products. The best choice depends on your application and cost target.
Is kaolin clay the same as china clay?
Yes. Kaolin and china clay are two names for the same white clay, made mostly of the mineral kaolinite. The name kaolin comes from Gaoling (Kao-ling), the hill near Jingdezhen in China where it was first mined for porcelain.
Which kaolin grade is best for paint?
For interior whites and pastel shades, start with a high-whiteness grade such as L94+. For deep tints, primers, and industrial coatings, an L93 grade usually works well at a lower cost. Check grit, oil absorption, and effect on viscosity in your own formulation.
Can kaolin clay be used in rubber?
Yes. Kaolin is widely used as a non-black filler in rubber to add stiffness, aid processing, and reduce compound cost. Low moisture and low grit are important, and white or light-coloured rubber goods benefit from a higher-whiteness grade.
What kaolin is used in paper?
Paper uses kaolin as a filler to improve opacity, smoothness, and printability, and as a coating pigment in finer, higher-brightness grades. Paper mills specify ISO brightness and particle size, so share those targets with your supplier before trialling.
What should a kaolin certificate of analysis include?
A useful kaolin certificate of analysis should include whiteness with the scale and method used, Fe₂O₃, TiO₂, Al₂O₃, moisture, residue on sieve, and particle size distribution where relevant. It should also carry a batch or lot number so each shipment can be traced.
How do I test a kaolin sample before a bulk order?
Test the sample in your own formulation alongside your current kaolin, under identical conditions. Check the parameters that matter for your product — fired colour for ceramics, viscosity and grit for paints, moisture and cure for rubber — then run a pilot batch before locking the specification into a contract.
Does Pacific Minerals supply custom kaolin grades?
Yes. Pacific Minerals offers custom grades as part of its long-term partnership approach, along with supply contracts, annual volume commitments, and planned dispatch cycles. Share your application and target parameters to discuss a custom specification.
Where is Pacific Minerals kaolin clay produced?
Pacific Minerals produces kaolin clay at its operations in Dhaneti, Bhuj-Kutch, Gujarat, India, supported by direct access to mineral deposits and a semi-automated 24×7 production facility.
Which ports does Pacific Minerals export kaolin from?
Pacific Minerals exports through Mundra and Kandla ports in Gujarat, both less than two hours from its facility, which supports fast outbound logistics for international buyers.
What is the HS code for kaolin clay?
Kaolin clay is classified under HS code 2507, which covers kaolin and other kaolinic clays, whether or not calcined. Confirm the full national tariff line with your customs broker for your destination country.
How does Pacific Minerals check kaolin quality?
Pacific Minerals follows a batch-wise QA process that includes sieve analysis, moisture content check, whiteness (L value) measurement, impurity screening, load verification, and pre-dispatch inspection. Each shipment is supported by a lab test report.
What is the minimum order quantity for kaolin clay?
The minimum order quantity for Pacific Minerals kaolin clay is 28 MT. Contact our team with your grade, volume, and destination for a tailored quotation.
How is kaolin clay packed for shipment?
Pacific Minerals kaolin clay is packed in jumbo bag (with and without pallets), 25kg or 50kg bags, custom packing. Packaging can be discussed based on your handling equipment and destination.
Get a Kaolin Grade Recommendation from Our QC Team
Not sure whether L93 or L94+ is right for your product? Tell us your application, end product, target whiteness, monthly volume, and destination port. Our quality team will recommend a starting grade and arrange a sample with its lab test report.
• Call / WhatsApp: +91 91733 80265
• Email: info@pacificmineral.in
• Address: Pacific Minerals, Survey No. 46, Village Dhaneti, Nadapa Road, Bhuj-Kutch, Gujarat – 370020, India
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