MC Paint will allow you to draw on blocks using an interface similar to the standard Windows Paint simple raster graphics editor. It is enough to use a new brush on the desired block. Have fun!
Screenshots:
How to install:
Download and install Minecraft Forge.Download the mod.
Go to %appdata%.
Go to the C:\Users\User_Name\AppData\Roaming\.minecraft\mods folder.
Drag and drop the downloaded .jar file into it.
If one does not exist you can create one.
Play and enjoy!
Download Mod:
1.13.2mcpaint_1.13.2_1.3.1.jar [0.13 Mb]
1.12.2
mcpaint_1.12.2_1.2.3.jar [0.13 Mb]