I like to think in terms of batter percentage.
Here's my usual process:
- Double check my loaf mold volume - it can hold 50oz.
- Input my recipe into Soapee, make sure that my total batter weight (oils, lye solution, fragrance) is close to 50oz.
- Decide on my design. Let's say I want a design with 4 equal layers. That means I will need to divide my batter 4x, each division being 25%. So if I have 50oz of batter, each division should be around 12.5oz.
- I'll get my containers ready: 1 large, 4 smaller ones. In the 4 smaller ones, I will mix my micas with oil.
- I will make my batter using the 1 large container - just stickblending to emulsion - I want lots of working time here.
- I'll put the first small container on the scale, add 12.5oz of batter and mix with a spatula to incorporate the mica.
- Do the same for the other 3 containers.
- Pour!
Now - you can get a lot more complex with this and it can become pretty easy to eyeball the percentages you want, especially in layered/geometric designs. If you want to do a thin layer on the top and bottom and a thick layer in the center, you could divide the batter into 3 portions of 10%, 80%, 10%. For example.