Carnations make a great filler flower for wedding sprays. I usually make them in white so that I can color them as needed. First roll out the gumpaste and cut with Wilton's carnation cutter.
I use a Cel-mat and the small Cel-stick to ruffle the edges. This is done by taking the round end of the stick and pulling the paste to the outer edge. Notice in the above picture that a pre-preped bud is used to insert into the petal.
You simply pull the gumpaste ruffle up around the center. With one row of petals on the pre-preped bud, I allow this to dry overnight.
Depending on the size needed will determine the number of ruffle layers you will need to attach. Once the first row of petals has dried overnight, you will be able to add all the additional petal layers making the flower as large as you would like (I sometimes use an egg carton which I cut into cups as a final support, I then allow the finished flower to dry several days)
When the flowers are needed I can color them by airbrush or petal dust.