Chelle, maybe it would help to see the steps along the way. I just let it all dry between layers, but this might help.
Black
then added polka dots over the dried black
Then I painted the first coat of the flower over the polka dots
Then I just kept on painting one color at a time over it as it dried till I finished what you saw in the article.
It's just paint but I let it dry between each coat of color.