I got a Paper Wall light today and changed its design to a custom design. Now I can't place it on the ground outside. Is it because I put a custom design on it or what??
There's a lot of things you can't do with it, including give/sell it to villagers or attaching it to letters. I'm guessing the reason is the only way you can share a custom designed item is to have the recipient also save your design pattern, which only a live person can do, so the game designers workaround was to not let you do anything with it aside from display it (and sell to friends via Retail).