1.   This technique is only a success on a raw timber or raw brick surface.
2.   Mix equal quantities of paint and water together and apply onto the surface with a paint brush (small areas at a time) and evenly spread and wipe with a damp cloth.  A clean, colourless, damp
mutton cloth works well.
3.   More than one colour can be used.  Wait for the first colour to dry before starting to wash with the next.