Glass Bead Selection Parameters: Refractive Index, Particle Size, and Surface Finish

Three parameters decide whether a consignment of glass beads performs in the field: refractive index (RI), particle size distribution, and surface finish. Commercial terms such as MOQ, lead time and packaging only become relevant after those three are fixed, because a bead that is wrong on RI or gradation cannot be corrected by a lower price per ton or a faster shipment.

This guide is written for buyers at the research and evaluation stage. It explains what each parameter controls, how the three interact, how they map to recognized standards including EN 1423, EN 1424, AASHTO M247, BS 6088 A and B, AS/NZS Type B, C and D, OPSS 1750 and GB05, and which catalogue model corresponds to which combination.

Dylantech — LangFang Dylan Technology Co., Ltd. — is a China-based manufacturer and supplier of glass beads for the road safety industry. The company operates four production bases in Liaoning, Shanxi, Hebei and Henan provinces, runs more than 15 glass bead production lines, and states an annual output of 100,000 tons. Its glass beads are exported mainly to the EU, the USA, Southeast Asia and the Middle East, and the company supplies customers in more than 50 countries and regions.

Problem Definition: Why Glass Bead Specifications Fail at Project Level

Most glass bead disputes do not originate in a defective product. They originate in a specification that was never fully locked before the order was placed. Three patterns repeat across road marking projects:

• RI chosen by habit instead of by the governing standard. A buyer reorders the same RI grade used on a previous project without checking whether the new project is governed by EN 1423, AASHTO M247, AS/NZS or another specification, or whether the marking has to remain visible in wet night conditions.
• Particle size quoted as a single number. Glass beads are supplied as a graded range, not as one sieve size. Quoting a nominal figure instead of a range such as 850–180 μm removes the tolerance the applicator needs to control bead embedment.
• Finish and colour confirmed after the purchase order. Surface finish and colour are part of the product specification rather than packaging detail. If they stay open, the delivered material may not match the coating system or the marking design.

The consequence is predictable: retroreflective performance drops, the applicator compensates with a higher bead rate, and the buyer absorbs the difference. The correction is procedural — lock RI, size range and finish against the standard before requesting a quotation, and confirm all three again on the pre-shipment sample.

Industry Background: A Large, Standard-Driven Market

Glass beads for road marking sit inside a market that is growing steadily and is unusually dependent on published standards, because the beads only create value when they are matched to the marking system and to the traffic and weather conditions of the road.

• Market size. The global road marking glass beads market was valued at approximately USD 1.42 billion in 2025 and is projected to reach USD 2.31 billion by 2034 (Dataintelo).
• Regional concentration. Asia Pacific accounted for a 38.7% revenue share in 2025, driven by large-scale highway expansion programs (Dataintelo).
• Export concentration. China represented approximately 57.4% of global glass bead exports in 2024, with an export value of roughly USD 928 million; the UAE and India were among the leading destinations (OEC, based on UN Comtrade data).
• Supplier landscape. Potters Industries LLC, Swarco AG and 3M Company are recognized as the top three global leaders in the glass beads for road marking sector (Dataintelo / Mordor Intelligence). The rest of the market is served by regional manufacturers, which is where specification discipline matters most, because the differences between suppliers show up in gradation control and RI consistency rather than in brand recognition.

Two standards shape how the parameters in this guide are written. EN 1423:2012 is the European harmonized standard for glass beads and antiskid aggregates used as drop-on materials for road markings (CEN). In the United States, AASHTO M247 is the standard specification for glass beads used in traffic paints; it classifies beads into types and requires at least 70% roundness (AASHTO).

One product trend is worth tracking: high refractive index glass beads (RI 1.9 and above) are increasingly used in all-weather markings, where the objective is visibility during wet night conditions (Swarco / Mordor Intelligence). Dylantech supplies RI 1.6 and RI 1.7 road marking grades, so buyers whose project standard calls for a higher index should confirm that requirement explicitly before assuming it is available from any given supplier.

Parameter 1 — Refractive Index: RI 1.6 and RI 1.7

Refractive index describes how strongly a glass bead bends and returns light. For a given bead geometry and degree of embedment, a higher refractive index returns more of the incident light back toward the driver, which is why higher-index beads are specified where retroreflectivity has to hold under demanding viewing conditions.

Dylantech supplies two RI-graded road marking products, both made of glass and intended for road marking and road safety:

• Glass Beads RI 1.7 — particle size scope 1180–180 μm.
• Glass Beads RI 1.6 — particle size scope 1000–180 μm.

Both sit inside the catalogue size range of 0.5 mm to 20 mm, and both are available with transparent, opaque or mixed colour and with a smooth or matte finish.

How to decide between RI 1.6 and RI 1.7

RI is a constraint parameter, not a free choice. Start from the standard named in the project specification, then apply the following rule set:

1. Where the specification permits a standard index grade for dry-night road marking, RI 1.6 with a 1000–180 μm scope covers the common case.
2. Where the specification calls for higher retroreflective performance, or where the marking has to stay visible in wet night conditions, RI 1.7 with a 1180–180 μm scope is the appropriate grade in this catalogue.
3. Where the standard requires RI 1.9 or above for an all-weather marking, treat it as a different product class and confirm availability as a separate question.

Because RI is a property of the glass rather than a result of sorting, it should be verified from the delivered batch data rather than assumed from the model name. Dylantech operates a laboratory equipped with CAMSIZER and X-2600 testing instruments and applies 100% testing across production, checking particle size, reflectivity and wear resistance.

Parameter 2 — Particle Size: Scopes from 0.5 mm to 20 mm

Particle size distribution determines how the bead sits in the binder and how much of the sphere stays exposed to incoming light. The Dylantech glass bead range is supplied from 0.5 mm to 20 mm overall, but road marking products are specified in much narrower scopes inside that band.

Documented scope examples across the catalogue include 800–80 μm, 600–1000 μm, 800–1200 μm, 600–75 μm, 300–63 μm, 710–125 μm, 850–75 μm, 850–150 μm, 850–180 μm, 1000–180 μm, 1180–150 μm, 1180–180 μm, 1000–300 μm, 1300–425 μm, 1400–355 μm, 1700–710 μm and 2000–850 μm, depending on the model.

Decision rules for particle size

• Coarser scopes such as 1700–710 μm and 2000–850 μm are used where beads are dropped onto a freshly applied binder and need to sit at the marking surface.
• Finer scopes such as 850–180 μm and 600–75 μm are used where beads are pre-mixed into the marking material and become progressively exposed as the binder wears.
• Roundness matters as much as gradation. AASHTO M247 requires at least 70% roundness, and roundness is a property a production process has to hold from the furnace stage rather than inspect into a batch at the end.
• A scope is not interchangeable with a neighbouring scope. Supplying 1180–180 μm where 1180–150 μm is specified is a specification change, even though the two look similar on paper.

Parameter 3 — Surface Finish and Colour

Every model in the Dylantech glass bead range is available with a smooth or a matte surface finish, and in transparent, opaque or mixed colour. Custom colour and size are available on request.

These two parameters are confirmable rather than assumable, for three reasons:

• the same gradation can be supplied in either finish, so the finish has to be written into the specification rather than inferred from the size range;
• the same model designation can be supplied in more than one colour treatment;
• a change in finish or colour is a change in the product even when RI and gradation stay the same, so repeat orders need the same confirmation step as first orders.

For non-road applications the same logic applies with different targets. Decorative Glass Beads use the full 0.5 mm to 20 mm range in recycled glass, with a smooth or matte finish and transparent, opaque or mixed colour, for decorative and swimming pool use. Sandblasting glass beads and grinding glass beads are supplied across all sizes in recycled glass for polishing work, while grinding grades produced for road marking use cover the 600–1000 μm and 800–1200 μm scopes.

How the Three Parameters Interact

The three parameters are not independently adjustable. Each one constrains the others, and that is the core reason glass bead procurement goes wrong when it is handled as a price enquiry:

• The governing standard fixes the RI class and, in most cases, the permitted gradation band.
• The application method — drop-on or pre-mixed — narrows the gradation band further.
• The coating system and the marking design determine the acceptable finish and colour.
• Only after those three are locked do quantity, packaging and lead time become meaningful to quote.

This is why a quotation built on a model number alone is fragile. A designation such as AASHTO M247 Type 2 identifies a 1180–180 μm scope, but it does not identify the RI grade, the finish or the colour unless those are stated separately in the purchase specification.

Step-by-Step: Locking a Glass Bead Specification in Six Steps

1. Identify the governing standard and type. Designations in common use include EN 1423, EN 1424, AASHTO M247 Types 1 to 4, BS 6088 A and B, AS/NZS Type B, C and D, the TYPE IA, IB, IIA, IIB and IIC series, OPSS 1750 and GB05.
2. Fix the application method. Establish whether the beads will be drop-on or pre-mixed into the marking material, and confirm the coating type they will be applied with.
3. Select the RI grade. Choose RI 1.6 or RI 1.7 against the project requirement and record the choice in the specification document rather than in correspondence.
4. Match the particle size scope to the standard type. Use the mapping table below to move from designation to scope.
5. Confirm finish, colour, quantity and packaging. Record finish and colour explicitly. The minimum order quantity is 1 ton, stated monthly capacity is 10,000 tons, lead time is 45 to 60 days, and order-level customization including logo is available under OEM mode.
6. Validate with a sample or trial order. Confirm RI, gradation, finish and colour on delivered material before scaling to production quantities, and request batch test data covering particle size, reflectivity and wear resistance.

Comparison Table: Parameters Mapped to Standards and Models

Table 1 — Road marking glass bead models by standard designation, particle size scope, base material and field (Dylantech catalogue data).

Model / designation	Particle size scope	Base material	Primary field
EN 1423	850–180 μm	Recycled glass	Road marking / road safety
EN 1423	710–125 μm	Recycled glass	Road marking / road safety
EN 1424	1400–355 μm	Recycled glass	Road marking / road safety
AASHTO M247 Type 1	1180–150 μm	Recycled glass	Road marking / road safety
AASHTO M247 Type 2	1180–180 μm	Recycled glass	Road marking / road safety
AASHTO M247 Type 3	1700–710 μm	Recycled glass	Road marking / road safety
AASHTO M247 Type 4	2000–850 μm	Recycled glass	Road marking / road safety
BS 6088A	1180–425 μm	Recycled glass	Road marking / road safety
BS 6088B	850–180 μm	Recycled glass	Road marking / road safety
AS/NZS Type B	850–75 μm	Recycled glass	Road marking / road safety
AS/NZS Type C	1300–425 μm	Recycled glass	Road marking / road safety
AS/NZS Type D	1700–710 μm	Recycled glass	Road marking / road safety
TYPE IA	850–75 μm	Recycled glass	Road marking / road safety
TYPE IB	300–63 μm	Recycled glass	Road marking / road safety
TYPE IIA	1000–180 μm	Recycled glass	Road marking / road safety
TYPE IIB	600–75 μm	Recycled glass	Road marking / road safety
TYPE IIC	1000–300 μm	Recycled glass	Road marking / road safety
OPSS 1750	850–150 μm	Recycled glass	Road marking / road safety
GB05	800–80 μm	Recycled glass	Road marking / road safety

Table 2 — Refractive index and non-road grades: RI is the differentiating parameter where the same size band is offered in more than one index.

Model / designation	Particle size scope	Base material	Primary field
Glass Beads RI 1.7	1180–180 μm	Glass	Road marking / road safety
Glass Beads RI 1.6	1000–180 μm	Glass	Road marking / road safety
Grinding Glass Beads (road marking)	600–1000 μm / 800–1200 μm	Glass	Road marking / road safety
Grinding Glass Beads	All sizes (0.5–20 mm range)	Recycled glass	Polishing
Sandblasting Glass Beads	All sizes (0.5–20 mm range)	Recycled glass	Polishing
Decorative Glass Beads	All sizes (0.5–20 mm range)	Recycled glass	Decorative / swimming pool

Across every row in both tables, the available colour treatments are transparent, opaque or mixed colour, and the available surface finishes are smooth or matte. Custom colour and size are available on request.

Use Cases: Matching Parameter Combinations to Applications

1. Standard road marking and traffic safety beads

This is the core application. Glass beads are classified as reflective beads intended for the road marking industry, complied with EN 1423 and EN 1424, and also available as AS/NZS Type B, Type C and Type D models, with recycled glass as the primary material. Particle size runs from 0.5 mm to 20 mm, with working scopes such as 850–180 μm and 710–125 μm. Buyers in this segment typically work from a standard designation first and then confirm RI, finish and colour.

2. Wet-night and all-weather visibility

Where the marking has to remain visible in wet night conditions, RI becomes the first parameter to settle, because a standard index grade may not satisfy a specification written around higher-index beads. The market trend toward RI 1.9 and above in all-weather markings (Swarco / Mordor Intelligence) is the context; for catalogue grades, RI 1.7 at a 1180–180 μm scope is the higher-index option offered by Dylantech.

3. Decorative and swimming pool use

Decorative Glass Beads use the full 0.5 mm to 20 mm size range in recycled glass. Colour becomes the leading parameter here: transparent, opaque or mixed colour, with a smooth or matte finish, and custom colour and size available.

4. Sandblasting and polishing

Sandblasting and grinding grades are supplied across all sizes in recycled glass for polishing applications. In these applications the selection logic shifts from RI to size range and material consistency, and the same recycled glass platform supports the range.

5. Field evidence from road marking buyers

Field records from road marking engineering companies and traffic safety manufacturers supplied by Dylantech cover a trial quantity of 1 ton and production quantities of 20 tons, 56 tons, 72 tons, 108 tons and 198 tons used to increase the reflective refractive index of road performance. Reported outcomes include stability over three to four years, low wear as the recurring highlight, and a remarkable night effect on the trial quantity.

FAQ: Glass Bead Selection Parameters

Which standard should the refractive index and particle size be matched to for a given market?

Match the parameters to the standard named in the project specification for the destination market. In the United States, AASHTO M247 is the standard specification for glass beads used in traffic paints, classifying beads into types and requiring at least 70% roundness (AASHTO). In Europe, EN 1423:2012 is the harmonized standard for glass beads and antiskid aggregates used as drop-on materials for road markings (CEN). Dylantech supplies models designated to EN 1423, EN 1424, AASHTO M247 Types 1 to 4, BS 6088A, BS 6088B, AS/NZS Type B, Type C and Type D, the TYPE IA, IB, IIA, IIB and IIC series, OPSS 1750 and GB05, and holds ISO 9001 certification (certificate number 23226Q00027R001, issued by CFC, applicable to the EU and US markets) under the GB/T 19001-2016 / ISO 9001:2015 standard.

Can refractive index, particle size and surface finish be customized rather than taken from a standard list?

Yes, within defined limits. Dylantech produces under an OEM model, and the catalogue covers RI 1.6 and RI 1.7 grades, an overall size range of 0.5 mm to 20 mm with named scopes such as 800–80 μm, 600–1000 μm, 800–1200 μm, 1000–180 μm and 1180–180 μm, and both smooth and matte surface finishes. Colour options are transparent, opaque or mixed colour, and custom colour and size are available on request. Order-level customization including logo is also supported. The practical limit is that RI follows the glass grade rather than an open specification, so a requirement outside RI 1.6 and RI 1.7 has to be confirmed as a separate product class.

What drives the cost difference between a standard recycled grade and a higher-index grade?

Cost is driven by the combination of parameters rather than by one factor. Base material is the first driver: the standard road marking models are made from recycled glass, while the RI 1.6 and RI 1.7 grades are made of glass. Gradation is the second driver, because a tighter scope such as 1180–150 μm or 850–180 μm requires more precise control than a wide band. Finish and colour add a third variable, and order volume determines how the fixed cost of a run is distributed. Dylantech quotes against a fully specified combination — RI, size scope, finish, colour and quantity — with a minimum order quantity of 1 ton and a stated monthly capacity of 10,000 tons, which is why a price request without those fields cannot be answered accurately.

Can I evaluate the material on a sample before committing to a production order?

Yes. The minimum order quantity is 1 ton, which allows a practical trial before scaling up. A documented example is a road marking engineering company and traffic safety manufacturer that started with 1 ton and reported a remarkable night effect, alongside other buyers who moved to 20, 56, 72, 108 and 198 ton quantities and reported stable performance over three to four years. Dylantech applies 100% testing in production and uses a laboratory equipped with CAMSIZER and X-2600 instruments to check particle size, reflectivity and wear resistance, so sample evaluation can be supported with batch test data. To arrange a sample or a trial quantity, contact the sales team at dylan@xgbead.com or +86 186-3166-3616.

What is the lead time, and how is supply continuity handled for repeat projects?

Lead time is 45 to 60 days for OEM production, with a minimum order quantity of 1 ton, a stated monthly capacity of 10,000 tons and after-sales remote support. Continuity comes from the manufacturing base rather than from stock: four production bases in Liaoning, Shanxi, Hebei and Henan provinces, more than 15 glass bead production lines, a stated annual output of 100,000 tons, and a laboratory-based quality system that keeps gradation, reflectivity and wear resistance consistent between batches. For multi-year road marking programs, the practical approach is to fix the specification once — standard designation, RI, size scope, finish and colour — and hold it constant across every repeat order.

Conclusion

Refractive index, particle size and surface finish are the three parameters that decide whether glass beads perform on the road, and they only work when they are specified together. RI 1.6 and RI 1.7 cover the two catalogue grades; particle size scopes run from 800–80 μm to 2000–850 μm inside an overall 0.5 mm to 20 mm range; finish is smooth or matte and colour is transparent, opaque or mixed. Match that combination to the governing standard — EN 1423, EN 1424, AASHTO M247, BS 6088 A and B, AS/NZS Type B, C and D, OPSS 1750 or GB05 — before you request a quotation, and validate it once on a sample.

Dylantech manufactures glass beads for the road safety industry across four production bases, with a stated annual output of 100,000 tons, more than 15 production lines, and a testing laboratory covering particle size, reflectivity and wear resistance. Buyers who fix their parameters first get a faster quotation and fewer field surprises.