It may be the way I'm using this feature and I've just missed it - it appears to me that you can't have a solid background to your swatch because the way it stacks/overlaps elements means that you will end up cropping some elements on some sides.
Try it just by putting a solid shape the exact size of the tile.
Any tips, hints, explanations guys would be helpful as what I'm doing at the moment is add the fill after the fact in appearance which I'd rather not have to do all the time.
I'm still missing something here - I don't think it's possible to work with a solid background without running into overlap problems. In my screenshot there's a selected flower that is overlapped by the background in other tiles. If I change the overlap options, a different flower gets cut off. And even if I add a color background on another layer in my file behind this design, it's not visible in pattern mode. Hmmm...
Red, You are right, I can just move that flower, and it is all about the overlap. I'm discovering when I'm working on a grid pattern with a solid background and the overlap is set as left and top, that it helps to concentrate the elements on the right and bottom edge of the tile (where you moved the flower to) - setting the stacking order of elements up that way avoids overlap problems. The tiles are like fish scales in the way they repeat. This is taking me a minute to get used to. I also started locking that background square just to avoid moving it accidentally as I work.
But in a half-drop repeat (brick by column) it gets really complex trying to manage the overlap with a solid background. I just think solid backgrounds complicate things a lot. It's entirely possible to design patterns in this mode without a background and add a solid background later, but I think solid backgrounds on a separate layer would be a helpful future improvement to this feature. It's important to be able to judge the contrast and color relationships as you work on a pattern.
I still have a lot more experimenting to do-
I like the fish scale analogy! Very discriptive.
Your suggestion of a 'background' option would be good - a simple check box that could call up the colour picker maybe?
Adobe if you are listening...
We are still getting used to this pattern maker too, but we have created some great, complex patterns that would have taken considerably longer in our old worklflow and yet maintain the editability.