It was a many step process. The rose petals are arranged in layers around the tube. Then the prepared tube is cast under pressure.
I have also made some blanks using the other method - which is to stir small blossoms into the resin and make a large block. This works well with small, loose flowers. Here is a photo of Palo Verde blossoms embedded. After drilling I reverse painted the blanks white, then glued the tubes in.
Thanks everyone for your kind comments! This is a great forum, and I have learned so much from reading other posts.
Donna