LRF (Luminous Reflectance Factor)

General Information  

The LRF (Luminous Reflectance Factor) is often confused with the LRV (Light Reflectance Value); sometimes the terms are even erroneously interchanged.

Primarily for safety reasons, Government agencies specify contrast requirements, mostly in interior applications. The intention of these regulations is to create surfaces that are visibly different and hence readily identified by the viewer - even those with vision colour deficiencies. The LRF is defined as the colour contrast between two material surfaces, and is calculated by mathematical formula that uses the LRV's of each material. As a general rule, the LRF will not be meaningful insofar as a Dryvit application is concerned.


Determining LRF values 

Apparently various government agencies specify contrast requirements in all sorts of interiors (from public buildings to railcars).

Contrast in percent is determined by:

       Contrast = [(B1 - B2)/B1] x 100

where B1 = light reflectance value (LRV) of the lighter area

and B2 = light reflectance value (LRV) of the darker area.

Note that in any application both white and black are never absolute; thus, B1

never equals 100 and B2 is always greater than 0.

Please remember: Light Reflectance Values, and therefore the resulting Luminous Reflection Factors, can differ between different finishes and supply plants!


Obtaining LRF Values

Contact us

Make sure you have the following information available: 

  • Type of Finish
  • Colour Number or Name


Acknowledgements:  Information offered in this datasheet has been obtained from, Color Learning: From The Experts.

This website uses cookies and other tracking technologies (also known as pixels or beacons) to aid your experience (such as viewing videos), as well as “performance cookies” to analyze your use of this website and to assist with marketing efforts. If you click the "Accept All Cookies" button or continue navigating the website, you agree to having those first and third-party cookies set on your device. If you do not wish to accept cookies from this website, you can choose to not allow cookies from this website by updating your browser preferences. For more information on how we use Cookies, please read our Privacy Policy.

Accept All Cookies

Stay Connected