A very clever idea from Germany’s Magiro.
A clear Plexiglas tube is shown together with two caps. A spectator can examine everything and then close the ends with the caps. The tube is placed in an opaque carrying tube for protection (just big enough to hold the clear tube) and to ensure that nobody can get to it anymore. The closed tube is handed to the spectator for safekeeping.
Using your favorite method (thump-tip, pull etc.) make a silk disappear. The carrying tube is opened and the clear tube removed. Despite the fact that the tube is still securely closed on both ends it can clearly be seen that the silk has appeared inside. The caps are removed as is the silk and then all could be examined again.
We include the silk and English instructions.