FreeDraw

In-world brush & eraser
This mod is using vanilla items. Default brush item is minecraft:brush, eraser item is minecraft:resin_brick, with specific CustomModelData.
/give @s minecraft:brush[minecraft:custom_model_data={floats:[-1]}]
/give @s minecraft:resin_brick[minecraft:custom_model_data={floats:[-1]}]

Draw color can be changed. Use /drawcolor RRGGBB(hex) to change draw color.
Default max points is 2048. All these can be changed in server config.