- Source: Drawdown card
Drawdown cards are used for testing paints and coatings through wet film preparation.
Black and white cards are used to measure both opacity and contrast ratio. By measuring reflectance values of both parts of the card one can gain a quantitative opacity value of a paint sample.
References
See also
Film applicator
Glossmeter – Instrument for measuring specular reflection gloss
Spectrometer – Used to measure spectral components of light