Crayons and the ability to draw on maps.

Crayons could be made out of wax, paper, and different dyes depending on its color. Crayons could be used to modify pixels on maps according to their color. Say you want to mark a big red X on a map but don't have the time or resources to build a massive x; you could just craft a crayon and draw an X. Now of course crayons would have a durability bar or "uses bar" to indicate how many pixels you can draw. To be able to draw in the first place you could use a cartography table, insert the map in first slot, and the crayon in the second slot and use the mouse cursor to draw. (The following 4 ideas are entirely optional and open to change) You could use banner patterns to make specific designs on the map with your crayons. When smelted in a furnace crayons within 10-20 points of full durability could be smelted for wax again. Crayons can be repaired by putting wax next to them in a 2x2 or 3x3 crafting grid. Glow berries or a glow ink sack could be used in the crayon crafting recipe to give the crayon a glowing effect. 

That is the end of my ideas for crayons. Simply just a way to draw on maps without needing to place 20,000 blocks. After all, there has to be some way those maps were drawn!