There are many ideas about the origin of glass paintings and ways to import them into Viet Nam. However, most researchers think that all the glass paintings in Hue were ordered from workshops of glass painting in Hoa Nam region (China) by Nguyen Dynasty. The glass paintings were enframed in gilded wood frames. The artisans used pastel mixed with glue or paint to draw or inlay nacre into back side of the glass. According to the glass paintings’ theme and value of fine arts, they include 3 main types:

- The high-class glass paintings describe and praise Hue’s beautiful sites and seasons with king’s poems attached. Most the paintings were drawn in cold colours. Today there are 40 high-class glass paintings in Hue.
- The glass paintings haven’t got the king’s poems but write painting’s theme. They were usually drawn in warm red. This is the type of painting which illustrates ancient stories in China’s history.
- The still-life glass paintings.

Although be the unique type of painting with specific characteristic of Hue royal fine arts, the glass paintings still haven’t received the proper investment and preservation. Researching on the origin and production technique of the glass paintings will help experts bring forward many ideas for preserving and restoring painting production technique.