I'm at work so can't follow the link, and have only made 2 bargellos so far, but I have 2 tidbits:
Use a digital camera with a black & white setting to take pictures of your fabrics so you can check your gradient.
Press the way they tell you to - it will help nest those corners together.
Have fun! I LOVE bargellos! I need to churn through a few more projects before I can do another one and I can't wait.
