Wood Sign

Use an item on this to change what's displayed. The item won't be consumed.
Overview
The Wood Sign is a craftable item that can display the image of any item that can be held in inventory. To put an image on it, hold the desired item in inventory and right-click the sign; the item is not consumed.
Wood Signs can be placed almost anywhere in Stardew Valley, both indoors and outdoors. They are useful as labels, reminders, and visual markers for storage rooms, paths, and other organized spaces. However, if a sign is placed in a villager’s walking path, it will be destroyed, so placement must avoid NPC routes when used outside the farm.
A special use for the Wood Sign is on a 
Because the sign reflects the held item’s image, it can serve as a simple display tool for many different item types. It does not remove the item used to set the image, which makes it convenient for reusing valuable items as visual labels.
Official description
Use an item on this to change what's displayed. The item won't be consumed.