Active Standard ASTM D344 | Developed by Subcommittee: D01.26
Book of Standards Volume: 06.01
Historical (view previous versions of standard)
Significance and Use
This test method evaluates the hiding power of a test paint relative to a comparison paint. The results have significance only within that relationship. It may be used for production control or quality comparisons.
When a paint is applied by brush or any other practical method, the opacity of the film is affected by variations in film thickness related to the application procedure and to the application characteristics of the paint. Two paints that hide equally well by this method might therefore differ considerably when applied with a doctor blade, since the latter method gives essentially perfect leveling. Different brushes or surface application conditions can likewise give different results.
Note 1—Test Method D2805 describes an instrumental method for quantitatively determining hiding power without reference to a material paint standard. The paint film is applied at a uniform thickness (for example, with a doctor blade), the film thickness is measured rigorously, and the opacity is evaluated photometrically. Hiding power is thereby determined with a high degree of precision.
Test Method D344 is less precise than Test Method D2805, but is more practical because it is responsive to the application characteristics of paints, and is simpler in concept and execution.
1.1 This test method provides for the qualitative and quantitative visual determination of the hiding power of a test paint relative to that of a comparison paint.
1.2 This test method describes only a brushout application procedure in specific detail, but its concepts are valid for other methods of application as well.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D16 Terminology for Paint, Related Coatings, Materials, and Applications
D1475 Test Method For Density of Liquid Coatings, Inks, and Related Products
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D2805 Test Method for Hiding Power of Paints by Reflectometry
D5068 Practice for Preparation of Paint Brushes for Evaluation
E1247 Practice for Detecting Fluorescence in Object-Color Specimens by Spectrophotometry
E1347 Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
E1349 Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45:0 or 0:45) Geometry
ICS Number Code 87.040 (Paints and varnishes)
UNSPSC Code 31211500(Paints and primers)