What is ISO 3233‑2 - Paints and varnishes about ?
ISO 3233‑2 is an international standard on paints and varnishes which covers the determination of percentage volume of non-volatile matter.
ISO 3233‑2 specifies a method for determining the non-volatile matter by volume (NVV) of coating materials by determining the practical dry-film density. This method determines the volume percentage of non-volatile matter in paints, varnishes and related products by measuring the density of a dry coating for any specified temperature range and period of drying or curing. The non-volatile matter content is determined in accordance with ISO 3251.
Using the non-volatile matter by volume results obtained in accordance with this document, it is possible to calculate the practical spreading rate of coating materials.
Note: ISO 3233‑2 is not applicable to coating materials which exceed the Critical Pigment Volume Concentration (CPVC).
Who is ISO 3233‑2 - Paints and varnishes for?
ISO 3233‑2 on paints and varnishes is useful for: 
- Paints and varnishes manufacturers
- Coating professional
Why should you use ISO 3233‑2 - Paints and varnishes ?
Dry film density is just the mass of the dry paint film divided by the volume of the dry paint film.
Non-volatile matter is defined as the coating content remaining after all water, solvents and other volatiles have been evaporated or removed. The amount of nonvolatile matter in a paint or coating can be expressed as either a weight or a volume.
With the use of ISO 3233‑2, you can calculate the spreading rate of coating materials which is the rate that is tied up with the application properties of the paint and reflects how far a paint would be spread by someone simply painting by 'feel'.
What’s changed since the last update ?
BS EN ISO 3233‑2:2019 supersedes BS EN ISO 3233‑2:2014, which is withdrawn.
BS EN ISO 3233‑2:2019 includes some technical changes with respect to BS EN ISO 3233‑2:2014. These are:
- The definitions and sources in Clause 3 have been updated
- Minimum mass of 25 mg of the coating on the plate has been added in 7.2.2, because measurements and simulation calculations demonstrate the need for a minimum mass for the coated panel
