I have a few packages of very old treated fabric used for sun printing. The package said if the fabric has turned blue (and it had, very blue) that it was old but would still work you just need to rinsed it well and let it soak for a while in clear water. I rinsed it and rinsed it and soaked it which did bring out some whites. I'm not sure if the images are permanent so I will use the fabric in projects that do not have to be washed. It was a fun experiment. I used some fabric that I had sun printed in a quilt and the images washed out and part of it turned yellow. I do learn - thus the non washable projects for this batch.