There are a couple of things to keep in mind when doing this type of soap with a piping technique:
1. Work at low temps (90 to 100 degree lye solution for me)
2. Choose a slow moving recipe
3. Select a fragrance that does not accelerate or discolor
My first attempt this time was this soap:
It is fragranced with Birthday Cake, and while it turned out okay, I thought I would like to try it again with a smaller tip to see if I could get more definition in the flowers (I use open-star tips for my rosettes).
Because I am fragrancing this one with Blackberry Sage, I pictured a light earthy green for the bottom and a muted purple topping. I actually colored the whole soap a very slight green, similar to the color you would have if you had used pomace olive oil in your recipe. I poured the bottoms, leaving some room at the top for the rosettes:
I remember (maybe from a tutorial of Amy's?) that if you place something on top of your mold, the soap underneath will set up a bit faster, so I placed a baking sheet on top of my molds while I prepared the rest of my soap, so that the base would be ready for my heavier rosettes.
I colored the rest of my soap with purple mica. It's a muddy purple, because the base was slightly green, but I think it works for this blackberry soap. I stickblended it until it was thick enough for piping and put it in my piping bag:
I test my soap, to make sure it will hold up for piping - this is holding it's shape well and looks good to go!
Working on the piping, I think the smaller tip is better...you can see the rosettes better:
It is also important to tap down your molds as you are piping your rosettes, it helps the rosettes to settle a bit in the base soap and spread out slightly toward the sides of the mold. Here they all are in the mold:
It's a very simple technique, but so versatile...I love the way these turned out! :)