But, then we are faced with the challenge of removing the raft from the item. And, I have had very little success cleaning the raft off an item completely.
In line with Jim's basic premise, that allowing water to dissolve some of the glue under a piece would facilitate removal, I've been using channels cut into the bottom of items to accomplish the same thing.
While he didn't mention it, the second benefit of Jim's observation is that having a raft makes it easier for us to get the palette knife under the item we are trying to remove. To accomplish this without a raft, we can chamfer the bottom edges to give us leverage for a palette knife to pry the item off the plate.
Both systems work. It's just a matter of preference as to which one you use in your own designs. But, when printing downloaded designs, Jim's suggestion of using a raft is the best alternative.
In Moment of Inspiration, the process of creating channels is very easy. Here is a short video that demonstrates an alternative to using a raft to facilitate easier removal.
The ease with which these kinds of operations are done in Moment of Inspiration is just one of the reasons why we chose it for our cadets as they learn to design and print in 3D.