I borrowed this idea for a Groovy Tie Dye Peace Sign Birthday Cake after looking at several sites for inspiration for our daughter's groovy 6th birthday cake.
I started with a white butter cake recipe that I enjoy. I crumb-coated the cake with a white royal icing. After that, I took the remaining icing and colored it with six different bright gel colors for our 'groovy' theme. I placed the colors into six different piping bags and cut off the tips of the bag to make about a 1/4 inch circle opening. Then I alternated colors and made designs of no particular kind all over the sides of the layers.
When that was finished, I took a toothpick and dragged it through the designs in a crisscross fashion. This will further intermingle the colors.
After that was done, I took the remaining icing and placed it into one piping bag, alternating the colors as I placed them in the bag. This bag had a large star tip to make the peace sign design on the top of the cake.
I started by piping stars all around the circumference of the top of the cake and then created the peace sign down the center. By alternating the colors of icing in the piping bag, the stars come out mixed up in a tye-dye design. It looks really cool!
When the top design was finished, I cut wax paper to be the width and circumference of the sides of the cake layers. I wrapped the wax paper around the sides ONLY and pressed gently to adhere it to the mix of color icing on the sides. Then placed the entire cake in the refrigerator for a couple of hours. When you take the cake out of the refrigerator, remove the wax paper and the side design will appear more like an interwoven tye-dye design.
I stored the layers separately until we arrived at the party and then assembled them on location. For the presentation, I took a square cake board and covered it with the same wrapping paper that matched the theme of the plates and decorations at the party. It completed the theme.
Have fun with this one. It was very easy to do and looked so professional when I was done. The cake received lots of compliments at the party.