The expanding circle is one of two methods of building the top of a coif. This method makes a circular patch which can then be attached to normal rectangular patches to finish the coif. The other method is to make five triangles and then to sew them together using 45 degree angle seams. I personally prefer the expanding circle method, which does not create any seams. Both methods can also be used wherever you need a circle, and thus come in handy for pouches and other such projects.

The most important step in these instructions is the expansion. Expansion rings are rings which are used to make a weave wider or taller. Without them, the circle would quickly become far too tight to be feasible.

Step 1: add some closed rings to an open ring and then close that ring. Lay the group out as shown. The single open ring (sometimes referred to as the "queen ring") will be the center of your coif. You want to pack a fair number of rings onto the queen ring, but you still should not have any problems getting the rings to lie more or less flat. None of the rings should be pushed into the middle of the queen ring because of the density of the rings. To make this easier, use a larger ring for the queen ring - 3/8" ID if you're using 5/16" ID rings, or 7/16" ID for a 3/8" ID piece, and so on. Call the outer rings Row 1.

Step 2: Add another row of rings in the Euro 4-1 style. That is, add another row of rings such that each ring passes through two adjacent rings in the previous row. I'm sure you can figure it out. Call this Row 2.

Step 3: Go around the circle adding rings through Row 1, in such a way that the rings only pass through one ring in the row. Space them regularly. They should not pass through Row 2 rings.

Step 4: Now add onto that row of normal and expansion rings. Each ring that you add should pass through two of the rings in the previous row, whether they be normal or expansion rings. Notice that each expansion ring now passes through three rings in total - one ring near the center and two in the row you just added.

That's the basic method for building a circular coif top. Just continue to build outwards, expanding when necessary. Unfortunately, there's no good way to give hard numbers for the amount of expansion you have to do; head sizes vary far too much. I generally just eyeball my circles to see if the weave looks too dense or too tight. If the latter, then I expand. Oh, and try not to put your expansions in the same location on different rows. Doing that will cause the coif to deform, creating a noticeable seam and losing the circular shape.