Is blue sun drying becoming more and more effective over time?

Photos will fade after being exposed to strong sunlight, but they can be restored after being left in the dark for a short time. Different from the conventional photography process, the blue sun method can obtain technically perfect photos through process control. In the production process, the blue drying method will show different effects with the changes of media ratio, coating method, strength and exposure time. At present, the color of blue drying method is mainly blue.