It looks to me like they are painted directly onto the cake top using black gel color that has been thinned or using airbrush color. I used a stencil to do something similar with asian writing on a cake I made a couple of years ago. (I don't have a picture of it.)
If it's not gel painted onto the fondant it might be an edible marker that was used to draw directly onto the fondant.
Great, thanks for the responses. I can use my projector and paint them on.
It looks like edible marker to me.
Okay. Another question, please. I am doing this cake in a 6 and 10". Do I stack them before decorating or do I just mark where the 6 will go and decorate the 10 with the stripes up to the mark?
I'd put the stripes on first.
ditto. i would mark where your top tier is going to be, make your stripes to go just slightly beyond that mark. that way when you place the top tier, it would give the illusion that the stripes go all the way across.
pretty cake... can't wait to see your version