Proper light
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
Tobacco shall not be inspected or sampled for the purposes of the Act except when displayed in proper light for correct determination of grade or other characteristics of tobacco. No tobacco shall be inspected or sampled for the purposes of the Act in the direct rays of the sun or by any artificial light which does not permit the inspector correctly to determine the grade or other characteristics of tobacco.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.