How to preserve an autograph?
The best way to preserve the signatures is to store the action figures wrapped in acid free paper in a sealed container away from light and extreme temperatures. If you want to display the figures, you should place them in archival or museum quality display boxes as they are made to protect the figure from exposure to UV rays or fluorescent lighting which can corrode the ink (especially since the signatures are in felt tipped marker). If you need advice on which specific containers would be best for you, talk to someone at a hobby shop. This is the most likely place to find the containers you will need and they will be best informed on which product is the best for your price range and specific needs.