Anyone know how to acheive this?

You steam them. Boil a pot of water and quickly pass the flowers over the steam a couple of times. Don't get them too wet or they'll soften.

ETA: Oh! and wait till their very dry before steaming, or they'll soften.

that will give you a slight sheen. if you want it very shiny, dust with a pearlized dust before steaming - that will be a more intense sheen. and if you want REALLY shiny, after you make the slowers spray wih confectioners glaze (no steaming needed).

I second the confectioners glaze. It comes out with a nice glossy sheen.

The steaming works while it's wet.. when it dries, it loses it's shine..

Get the confectioners's glaze..

Does confectioner's glaze help "lock" out humidity, or does it get soft under high humidity also?

where would one find confectioner's glaze? Or can you make it?

Thanks
JUlia

I ordered mine from CK Products.

I have Lesley Herberts "Complete Book Of Sugar Flowers", to get that sheen on gumpaste flowers she suggests either using a vegetable spray or the confectioners glaze.
I am practicing roses for an upcoming cake, so I sprayed the gumpaste flower with the store brand vegetable spray I use, thinking that it would not dry, would have that slick greasy feel...well to my surprise it did dry and to a nice gloss as well.
You may want to try this for yourself before spending money for the conf. glaze.