In this piece, Carolus uses the glass enamel medium to its fullest, creating effects that would not be possible in an oil or acrylic painting. He creates areas of shimmer and reflection in the gold lining and trim of the subject's wrap, and within the folds of the green overcoat.
Please see details in photos #3, 4, and 5. These effects change with the light and the angle of viewing. Metal, easel-back frame that appears to be bronze. Metal appears to have had a gold-tone finish (most visible on the back), which has tarnished and/or worn. The top cover of the frame hinges back and down to allow access to the painting.
The frame is of the same period as the painting and appears to be designed to house curved enamel paintings such as this. Painting is in excellent condition. Frame has some wear and/or tarnishing as shown in the photos. Your painting will be packed carefully and securely.