Different coating applications require different aluminium paste grades. Automotive coatings, industrial coatings, plastic coatings and printing inks can have different requirements for metallic brightness, particle size, dispersion and compatibility.

Choosing the right aluminium paste before production can therefore help improve coating appearance and reduce formulation problems.

1. Start With the Coating System

The first step is to identify the coating system in which the aluminium paste will be used.

Aluminium paste should be selected according to its compatibility with the resin, solvent and additives in the formulation.

2. Consider the Required Metallic Effect

The desired appearance is another important factor.

If the target is a smooth and uniform metallic appearance, a finer aluminium paste grade may be appropriate. For stronger sparkle or a more pronounced metallic effect, a larger flake size may be considered.

The final appearance also depends on pigment orientation, concentration, coating thickness and application conditions.

3. Choose Between Leafing and Non-Leafing Aluminium Paste

Leafing aluminium paste and non-leafing aluminium paste provide different pigment orientations within the coating film.

Leafing aluminium paste tends to migrate toward the coating surface and can provide a strong metallic and reflective effect.

Non-leafing aluminium paste remains distributed throughout the coating film and is often selected when the pigment needs to be integrated more uniformly into the coating.

The choice should be based on the formulation and final performance requirements rather than particle size alone.

4. Check Dispersion Performance

Good dispersion is essential for a consistent metallic effect.

Poor dispersion can cause:

• Uneven metallic appearance
• Pigment agglomeration
• Reduced brightness
• Surface defects
• Batch-to-batch variation

When evaluating aluminium paste, manufacturers should test its dispersion behaviour under their actual mixing conditions.

High-shear processing should also be carefully controlled because excessive mechanical force may affect the aluminium flakes.

5. Evaluate Compatibility and Stability

Aluminium paste should be compatible with the coating system and maintain stable performance during storage and application.

For water-based formulations, special attention should be paid to water compatibility, storage stability and gas-generation control.

For solvent-based coatings, compatibility with the selected resin and solvent system should be evaluated.

6. Test Before Bulk Purchase

A product specification sheet is useful, but laboratory testing remains important before placing a large aluminium paste order.

Testing the actual formulation can help determine whether the aluminium paste is suitable for production.

Conclusion

Selecting aluminium paste is not simply a matter of choosing the finest or brightest grade. The right product depends on the coating system, metallic effect, particle size, pigment orientation, dispersion and application conditions.

By evaluating these factors and testing samples before bulk purchase, coating manufacturers can select an aluminium paste grade that better matches their production requirements.