Here is the latest blog post. They have doubled their work rate so it will be interesting to see what it is by the end of the project. They do say about the double guilloche pattern being more complicated but they should find that it is one of the simpler ones, provided you work in a set way. The usual routine that i use is always;
- Place all the single white centre tesserae
- Black lines
It is the same every time and you can have someone doing each job with the other two following behind them.