Okay, I'm sure this has been talked about at some point. But I wanted to start a thread that was about how to prevent this from happening. First off I guess is the question of what causes the yellowing. Is it UV light, heat, or other factors. Second, does anyone know the type or chemical make-up of the plastics used for G1 toys so we can look up reactions to types of light? Third, what measures can we take to prevent yellowing. LMK your thoughts. I'm also looking for G1 Junker bots that have nice white parts. I want to run a few tests on the parts to see if I can indeed make them yellow under certain conditions. I'm hoping this might give us a clearer picture of what we can do to absolutly prevent the yellowing. For me yellowing seems to be the biggest problem for my collection. So far it's only happened on one figure, but it's enough to make me want to take drastic measure to make sure it doesn't happen with others. My Fort Max parts are a white as the day they were made, and I want him to stay that way.