Rubber lens hoods I am not quite sure where to post this but Ill try repair. I use collapsible rubber lens hoods on my lenses. It s good physical protection as well as a sunshade. Working with short zooms on the wide angle setting I collapse the shade. But eventually the continued working of the shade causes the rubber to wear and crack. Years ago when I worked in a printing plant the pressmen used s solution to rejuvenate the rubber rollers. And it extended their life, On a four color press there are a lot of rollers and they represent a considerable amount of money. So keeping them in good working condition was vital. The stuff came in one gallons cans and smelled to high heaven , but kept the roller soft and unglazed. I just wonder if anyone has ever used something similar to keep rubber pliable in reasonable sizes.