Coating Free Films and Coated Substrates: Different Specimen Constructions

The key distinction

The substrate can contribute to mechanical, optical or water-related behaviour. A film-only measurement may help characterize a material while leaving adhesion and complete-system performance unresolved. The report should state how the specimen was prepared and supported.

Practical checks

1. Identify whether the test used a free film or coated substrate.
2. Record thickness and preparation where relevant.
3. Match the conclusion to the tested construction.

Example

Illustrative example: a free-film property is used to claim the same behaviour on a particular painted panel. The interface and substrate were not part of that measurement, so the installed-system claim needs additional evidence.

Scope and limits

Do not peel a customer coating to create an improvised specimen. Use a suitable laboratory preparation method and preserve the distinction between material and system results.

Related guidance

• Teaching a Customer to Wash a Coated Car
• Coating Test Reports: Identify Whether the Specimen Was Scribed
• Random Sampling and Random Assignment in Coating Trials: Different Purposes
• Coating Rheometer Reports: Record Geometry and Gap

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.