blot (a blemish made by dirt)
plaster: coat with plaster; "daub the wall" material used to daub walls apply to a surface; "daub paint onto the wall" smudge: a blemish made by dirt; "he had a smudge on his cheek" an unskillful...
wattle and daub is made from clay,sand,fesise and straw
The painting was just a series of daubs of thick paint.
Mississippians