Scratches was an interesting discovery. I started by using a Processing script to apply virtual scratches to images. As such the results were not interesting, but I then trained a neural network, using image pairs consisting of an original and a scratched version, to perform a virtual scratching transform. The amount and form of scratching in the training examples was not uniform, adding more variation and randomness to the result. It turned out that the resulting scratch transform was much more interesting, there was softness and blending, bleeding of colour present in them.