I needed to add some details to the boats at some stage. Because they're small and mid-toned, I would usually put them on a later layer -- if they'd been any other colour than red. However, I find red the most difficult colour to work with because it's so transparent. If I leave the red to a later layer, it won't print well (all the earlier layers will show through, and it won't look bright red). So it's better to print when there are only light colours on the print.
But the other problem with red is that it's difficult to print on top of: when it's dry, its surface is more resistant to other ink on top.
Solution: I used an acetate stencil and printed the red just on the boats (and put some brown on some of the distant buildings). Now the red is exactly where I want it. I can cut away those areas from the block, and not have to worry about them again.
