The Fun Tak is safe for kids, and it does come off easily. Similar to silly putty, but stickier. Not sure why it is not opening. It was just a link to a site that sells it. I have even hung wall clocks with it.
My banner is home made :uhoh: so not sure if anyone will make one like that. I made it just for Devon, but it also worked at Lexington. I just used heavy material, and hemmed it top and bottom around a rope by hand one evening while watching a movie. I made felt letters and used fabric glue. Not fancy, but it is a banner. If you look close, you can see the ropes top and bottom tied off to the window bars. I have also used it lower to the side, just tied between 2 windows.
I use the binder as well for photos and information. You can see it on the little decorated table, just inside the doorway.

