How to Improve Scratch, Slip and Mar Resistance in Industrial Coatings

Scratch resistance, mar resistance and slip are related surface properties, but they describe different types of coating behavior. Improving them requires the right balance between binder strength, cure, surface additives, pigment loading and final-film compatibility.

Improving scratch, slip and mar resistance requires more than simply making a coating harder. Industrial coating additives can modify surface friction and resistance to visible marking, while the binder, cure level, film thickness, pigment and filler package determine much of the film’s underlying mechanical strength. The correct additive should therefore be optimized for the required surface property without compromising adhesion, gloss, recoatability or other final-film performance.

Industrial coatings are frequently exposed to handling, stacking, assembly, cleaning and contact with other surfaces.

A coating can have excellent color and adhesion yet still show visible scuffing, scratches or handling marks.

Surface-performance additives can help, but the correct approach depends on whether the problem is true film damage, superficial marking or excessive surface friction.

Scratch Resistance vs Slip vs Mar Resistance: What’s the Difference?

Scratch Resistance

Resistance to permanent damage caused when an object moves across the coating under sufficient force.

Mar Resistance

Resistance to visible surface marking, scuffing or appearance change that may occur without deep penetration of the film.

Slip

Describes how easily one surface moves across another and is related to surface friction.

A coating can feel very slippery yet still scratch under high load. Another coating may be mechanically hard but show visible mar because its surface friction or appearance is sensitive to rubbing.

Separate Bulk Film Strength From Surface Behavior

Scratch performance can be influenced by two broad areas:

Bulk Film Properties

Binder hardness, crosslinking, flexibility, film thickness and cure determine how strongly the coating resists permanent deformation.

Surface Properties

Surface friction, slip and the distribution of surface-active additives influence how easily objects move across the film.

This distinction is important because a surface additive cannot completely compensate for a film that is fundamentally too soft or insufficiently cured.

1. Start With the Binder and Cure Level

The binder forms the main continuous structure of an industrial coating.

Its chemistry strongly influences:

• Hardness
• Flexibility
• Toughness
• Chemical resistance
• Scratch resistance
• Adhesion
• Cure response
• Final film integrity

If the binder remains too soft for the intended application, adding a surface modifier may reduce friction but may not prevent deeper mechanical damage.

Some coating systems continue developing hardness after initial dry-to- touch. Compare candidate formulations after a controlled and relevant cure period.

Harder Does Not Always Mean Better Scratch Performance

Increasing hardness can improve resistance to indentation or deformation, but an excessively brittle coating may respond poorly to impact or flexing.

Industrial film performance often requires balance between:

• Hardness
• Flexibility
• Toughness
• Adhesion
• Impact resistance
• Surface friction

The best combination depends on the coated article and service conditions.

2. Use Surface Additives to Modify Friction and Surface Damage

Surface additives can alter the behavior of the top region of the coating film.

Depending on chemistry and formulation, suitable additives may help:

• Reduce surface friction
• Improve slip
• Reduce visible scuffing
• Improve mar resistance
• Support scratch resistance
• Modify surface feel

The additive must remain sufficiently compatible to avoid unwanted defects while still providing the desired surface effect.

Increasing surface migration or slip may improve handling resistance but can also influence intercoat adhesion, printing, bonding or recoatability. Final evaluation should include all downstream requirements.

3. How Lower Surface Friction Can Reduce Visible Damage

When two surfaces rub against each other, friction generates resistance to movement.

If surface friction is reduced, objects may slide more easily rather than dragging strongly across the coating.

This can sometimes reduce:

• Scuff marks
• Handling marks
• Stacking friction
• Visible mar
• Surface drag
• Minor handling damage

A slip additive primarily modifies surface friction. It should not be expected to create the bulk mechanical strength of the coating film.

Why Surface Additive Dosage Needs Careful Optimization

Too Little

The surface may show little improvement in slip, mar or scratch-related handling performance.

Too Much

Excess surface modification may affect gloss, adhesion, recoatability or compatibility depending on additive chemistry.

The selected dosage should deliver the required surface benefit while preserving the other properties of the coating.

4. Pigments and Fillers Also Influence Scratch and Mar Performance

Pigments and fillers affect the mechanical structure and surface characteristics of the coating.

Variables include:

• Particle hardness
• Particle size
• Particle shape
• Surface treatment
• Pigment volume
• Dispersion quality
• Binder-to-pigment balance
• Film roughness

A formulation change that improves one mechanical property can also alter gloss, application viscosity or film flexibility.

5. Maintain Good Pigment Dispersion

Poorly dispersed pigment or filler can create surface irregularity and inconsistent mechanical performance.

Flocculation can also change:

• Viscosity
• Gloss
• Surface smoothness
• Color development
• Film uniformity
• Storage stability

A well-stabilized pigment system provides a more consistent foundation for evaluating surface-performance additives.

Related guide: Wetting and Dispersing Agents for Coatings .

6. Evaluate Gloss Alongside Scratch and Mar Resistance

Surface additives can change how light interacts with the coating.

Depending on the formulation, a surface modifier may influence:

• Gloss level
• Surface smoothness
• Haze
• Appearance uniformity
• Tactile feel

This means a formulation should not be selected on scratch or slip performance alone.

If gloss is already a formulation issue, see: How to Improve Gloss and Color Strength in Paints .

7. Keep Flow and Leveling Under Control

A rough or poorly leveled film can show different friction and appearance behavior from a smooth coating.

Before concluding that mar resistance is poor because of the surface additive, check whether the film also shows:

• Orange peel
• Brush marks
• Roller texture
• Craters
• Poor substrate wetting
• Surface roughness

Surface appearance and surface durability should therefore be optimized together.

8. Check Adhesion and Recoatability After Increasing Slip

Some surface-active additives tend to concentrate toward the air-film interface.

This is useful for modifying slip, but it can also change how another coating, adhesive, ink or print layer interacts with the surface.

After changing the surface-additive package, evaluate:

• Intercoat adhesion
• Recoatability
• Printability where relevant
• Bonding performance
• Tape adhesion
• Surface contamination tendency

If the coated component needs to be recoated, printed, bonded or laminated, maximum slip can conflict with downstream processing.

Surface-Performance Priorities Depend on the Application

Water-Based vs Solvent-Based Surface Additive Selection

Water-Based Coatings

Compatibility with the aqueous system, surfactant package, foam control and film formation should be considered.

Solvent-Based Coatings

Resin compatibility, solvent environment, surface migration and cure conditions can influence additive behavior.

The same surface additive should not automatically be expected to perform identically across both formulation platforms.

How to Evaluate Scratch, Slip and Mar Performance

Because these properties are different, they should be evaluated separately rather than represented by one test result.

Prepare a control

Record the existing surface performance before adding or changing a surface additive.

Keep film preparation consistent

Use the same substrate, film thickness, application method and cure conditions.

Compare several dosage levels

Evaluate a controlled additive ladder within the appropriate screening range.

Measure each target separately

Evaluate scratch damage, visible mar and surface friction using methods relevant to the application.

Check side effects

Confirm gloss, adhesion, recoatability, blocking behavior and appearance before finalizing the formulation.

Properties to Include in a Surface-Additive Trial

• Scratch resistance
• Mar resistance
• Coefficient of friction / slip
• Gloss
• Haze
• Surface feel
• Adhesion
• Recoatability
• Film hardness
• Cure condition

A laboratory scratch result is useful, but the final formulation should also be exposed to the type of rubbing, handling, stacking or contact expected in actual use.

Scratch, Slip and Mar Resistance Troubleshooting Guide

Common Mistakes When Improving Scratch and Mar Resistance

Assuming Slip and Scratch Resistance Are the Same

Lower friction can reduce scuffing, but deep scratch resistance also depends on the mechanical strength of the coating.

Increasing Surface Additive Until the Film Feels Very Slippery

Maximum slip may create problems with adhesion, recoating or downstream processing.

Ignoring Cure Time

A partially cured coating can appear to have poor scratch resistance even when the fully developed film performs acceptably.

Changing Binder and Surface Additive at the Same Time

This makes it difficult to determine which change improved the result.

Judging Performance Only by Fingernail Scratch

Informal checks can be useful for screening, but controlled test methods provide more reliable comparisons between formulations.

Ignoring Gloss and Appearance

A technically stronger surface is not an improvement if it creates an unacceptable appearance for the end application.

A Practical Surface-Performance Optimization Sequence

Define the actual failure

Determine whether the issue is deep scratching, visible mar, scuffing or excessive surface friction.

Confirm binder and cure performance

Establish whether the underlying film has sufficient mechanical strength.

Screen suitable surface additives

Evaluate candidate slip or surface-modifying technologies at multiple levels.

Check appearance and adhesion

Confirm that gloss, haze, adhesion and recoatability remain acceptable.

Validate in real handling conditions

Reproduce stacking, rubbing, transport or mechanical contact relevant to the end use.

Information to Share When Requesting a Surface-Additive Recommendation

1. Water-based or solvent-based system
2. Binder or resin chemistry
3. Substrate
4. Current surface additive if any
5. Current dosage
6. Gloss level
7. Drying or curing conditions
8. Film thickness
9. Whether the problem is scratch, mar, scuff or slip
10. Whether recoating, printing or bonding is required

“Poor scratch resistance” can mean a deep cut into the film, a visible white mark, gloss change or simple surface drag. These may require different formulation approaches.

Surface & Industrial Coating Additives From Raj Speciality Additives

Raj Speciality Additives develops specialty additives for paints, coatings, inks and related formulation applications.

Surface-performance optimization should consider the complete coating, including binder strength, cure, pigments, surface chemistry and downstream processing requirements.

Important variables include:

• Binder chemistry
• Film hardness
• Cure condition
• Surface friction
• Gloss requirement
• Pigment loading
• Adhesion
• Recoatability

Explore RSA’s coating additive solutions or share your industrial coating surface-performance challenge for technical product-selection discussion.

Final Thoughts

Scratch resistance, mar resistance and slip should not be treated as one property.

Scratch resistance depends strongly on the strength and cure of the coating film. Slip controls surface friction, while mar resistance focuses on resistance to visible surface marking.

Suitable industrial coating additives can improve surface behavior, but they should be optimized together with the binder, pigment system, film thickness and curing process.

The best formulation delivers the required handling and surface durability without sacrificing gloss, adhesion, recoatability or downstream processing.

Related Technical Guides

Continue exploring coating surface performance and formulation troubleshooting from Raj Speciality Additives.

Frequently Asked Questions

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