Traditional Culture Encyclopedia - Photography and portraiture - What is the principle of cherry blossom umbrella?

What is the principle of cherry blossom umbrella?

I don't know if you are talking about the cherry blossom umbrella of Shuifeng, which probably means that the umbrella surface is coated with waterproof coating, but the part where the cherry blossoms appear is not, so when it rains, the rain will not stick to the coated part, but will stick to the uncoated part, so the cherry blossom pattern is formed ~ I don't know if lz understands it.