No sealer is included but do not need unless you want the borders to be permanent. Water-based sealer is acceptable to use. Even a thin base of clear glue works as well. Use a soft brush to apply. I avoid using oil based sealers in most of my wood crafting because I do not like the smell or the products you need to clean up with.
I have used the leaf flake style and foil leafing on some of my projects in the past. Both are comparable in results. You don't need the expensive Mona Lisa setting glue to make your own designs - I used Alene's foil glue and it works just as well.