I'm sure that my suggestion does not help you survive in Minecraft in any-way, so keep that mind.
Anyways, i was pondering all day.
Since signs you can write anything down, why can't you paint and draw anything on an painting?
Yes, drawing on an painting can be a little... stupid to some of you, yet here are some benefits.
Benefits on Minecraft:
Draw to remind you of something:
Ex: Remind you that around the corner there is lots of lava. (you can draw a warning sign)
Show direction to certain things are
Ex: draw arrows to places, i.e portals, enchantment room, mine etc.
So then, it Gives the player options to-do / paint, draw whatever.
Now, On faction servers, this can also help as-well:
Decoration of course
Sort out your chests with pictures to show what is in them
Ex: that chest has weapons, so above that chest, you draw an sword or somewhat.
And all of the benefits way of above.
Though, how would you paint if you have nothing to paint with?
Well, problem solved:
This recipe = a paintbrush which will be important soon!
Here would be how you would craft paint:
Now, the orange dye can be replaced by any dye. (green, blue, white etc.) (create the paint you want)
Since you got your paint brush and paint,and your original crafted painting, craft those three together in any two slot, (vertical, horizontal but must be beside each other - Ex Right XX Wrong X X)
Your final product will be "empty Canvas" you place it anywhere.
As well the size of your painting will change.
Simply hit the painting and lace it on an wall again until the size you want it to-be.
Once your satisfied, you can paint with whatever paint your crafted and is is in your inventory. (not chest)
Remember your painting pixels.
This also does not replace original paintings.
Note: once your done your painting, your done. And when you hit it, it clears and becomes an empty canvas.
If you have any questions, which i'm sure you do!
And if your not such a good artist, you can upload a picture on your computer, yet it may have to be pixelated or somewhat. (suggestion by Max_Cobar)