For sealing the
flowers I like Perfect Paper Adhesive. It's an acid free transparent
adhesive and sealer with a UV inhibitor. Using the matt formula, you
can't see it on the flowers, the gloss will give a shiny finish.
DMP (dried
material preservative) a pump spray available at most craft supply stores,
like Michael's. DMP seals and makes the flowers more pliable and offers a
slight amount of UV protection.
Krylon makes an
anti-UV clear acrylic sealer in a spray can that will probably be
available at any store that carries the DMP. It should also be available
at stores that sell spray paint.
Other options
include cold or heat lamination if you don't mind plastic on your
project. For some things, such as bookmarks this can be desirable.
I also use a
spray called "Clear Coat"...it's a plastic paint that's used on
playground equipment, usually sold in a can to be brushed on. It comes
in bright colors which is easy to find, but also clear which is harder
to find.
Clear Coat is
also available in a spray can which is harder to find, and even harder
to find in clear. They DO make it, I've been told at stores that they
don't... if anyone tells you this, don't believe them; just keep
looking. When you find it, buy as much as you can and horde it.