You don't. I use mine as a convience for travel. Easier to pack and it won't get creased. I use mine to ensure the razors edge is stropped correctly, it won't sag. I use mine to embed grit paste on to enhance the edge, especially during a shave if I don't want to wait for a stone to soak. I also use mine as a backup, when I've added strop dressing to my strop and don't have time for it to dry.