The way in which tiles join with one another can be controlled by altering the way in which they coalesce.
Do not attempt to join adjacent tiles.
(Default for new brushes)
Only join adjacent tiles of same brush.
Do not join with adjacent tiles of own brush, but join with tiles that were painted using any other brush.
Red lines illustrate that brushes join with one another.
Join with adjacent tiles of own brush and any other brush.
Only join with adjacent tiles that were painted using brush of zero or more specific groups.
|Own And Groups||
Join with adjacent tiles that were painted using same brush or brush of zero or more specific groups.