I can't post on challenges yet but I wanted to try the swirl challenge for April. This is 85% Olive oil, 25% Castor Oil, with eucalyptus eo (added to base oils), 2.5:1 water:lye, and 5% SF. Contrasting colors are yellow oxide and black oxide. I made some big mistakes, namely, waiting to mix my contacting colors after pouring base and pouring too much (too high of a base). I used a small square Tupperware container so I started with 15 oz base oil to achieve approx. 1.5 in tall bar. I have two final bars at approx 2.5x3.25x1.5.