The copyright over this work has expired because it is a work originated in Thailand and (1) it is a work created by a juristic person and 50 years have passed since its creation or first publication, according to section 19 of Thailand's Copyright Act, 2537 BE (1994 CE), and also (2) it is a work created by commission of or under control of the State and 50 years have passed since its creation or first publication, according to section 23 of the same Act.

This image or media is now in the public domain in Thailand because its term of copyright has expired (details). According to Sections 19–23 of the Copyright Act, BE 2537 (1994) (translation), works which meet one of the following conditions are in the public domain: This is a photographic work, audiovisual recording, motion picture, sound recording, or broadcast work, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship. This is a work of applied arts, and at least 25 years have elapsed its first publication or it was not published within 25 years of authorship. This is a work by a pseudonymous or anonymous author, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship. This is a work other than described above, and Its last author died at least 50 years ago, or Its last author died before publication and at least 50 years have elapsed since its first publication, or The author is a legal entity, and at least 50 years have elapsed since the first publication of the work or the work was not published within 50 years of authorship. This work was created or commissioned by the Thai Government, and at least 50 years have elapsed since its first publication or it was not published within 50 years of authorship. To uploaders : Please specify the kind of work, date of first publication or creation and other useful details. You must also include a United States public domain tag to indicate why this work is in the public domain in the United States.  Note that this work might not be in the public domain in countries that do not apply the rule of the shorter term and have copyright terms longer than life of the author plus 50 years. In particular, Mexico is 100 years, Jamaica is 95 years, Colombia is 80 years, Guatemala and Samoa are 75 years, Switzerland and the United States are 70 years, and Venezuela is 60 years.