This is a very interesting type of manuscript. I purchased this manuscript from Thailand. This manuscript was written in Thai language on thick papers both sided sandwiched by 2 hard boards. According to a specialist from British Library, this could be a manuscript on Tamra Ya which is a herbal treatise or recipe. Thanks to her for helpful identification.
Similar manuscript can be seen at this link
I dont have much information of this kind of manuscript and its writing tradition. I need to do more research on this manuscript and will update this entry later.
Item : Antique Thai Tamra Ya Manuscript
Content : Herbal Treatise
Dim : 12" x 4" x 0.5"
Date : 18-19th century
Copyist : anonymous
Origin : Thailand
Calligraphy : Thai
Design : Written in Thai scripts in black
Purchased Price :US