|Anyam gila weaving with its triangle grid.|
Braiding backgroundIn the usual flat braiding of three strands, the strand in the middle is exchanged with the strand on the left, then the strand in the middle is exchanged with the strand on the right, etc. Each strand thus spends only one move in the middle, but spends two consecutive moves on the right side or the left side. The weaving elements in anyam gila enjoy a similar lifestyle. They spend only one triangle inside the thickness of the fabric each time they pass through it (anyam gila is three plies thick,) they spend two triangles facing out each time they visit the front or the back face of the fabric. Overall the period is six triangles long: two in front, one in the middle, two in back, one in the middle.
The smallest anyam gila basketThe smallest anyam gila basket uses a single weaver, six triangles long, to wrap a two-sided triangle three-plies thick on each side. In the figure below, the single weaver has been cut somewhat narrow to clarify the structure.
|The smallest anyam gila basket.|
|The view from one tunnel to the next: mad weaving as a network of wildlife underpasses and overpasses.|
If the fabric is viewed as assembled from triangles, the meadow edge of a triangle always pairs up with the meadow edge of another triangle; scarp edges pair up with tunnel edges and vice-versa: there is a scarp above every tunnel, and a tunnel below every scarp.
Here is how the meadow/meadow fold looks in the basket above, viewed in cross-section.
|Cross-sectional view of the meadow/meadow boundary in the simplest anyam gila basket.|
And here is the same boundary in a larger basket where it is not folded:
|Cross-sectional view of a meadow/meadow boundary in a large basket (not folded.)|
At a meadow/meadow boundary nothing seems to happen---nothing changes on either side of the fabric. In the cross-sectional view we can see that a meadow/meadow boundary conceals a discontinuity in the middle stratum of the fabric. Therefore the choice of which diagonal of the quadrilateral is the meadow/meadow edge is not arbitrary, and the quadrilaterals on both faces of the fabric exactly coincide.
Here is how the tunnel/scarp fold looks in the basket above, as viewed in cross-section.
|The tunnel/scarp fold in the simplest anyam gila basket.|
|Tunnel/scarp boundary in a larger basket.|
In the cross-sectional view we can see that a tunnel/scarp boundary on one side of the fabric coincides with a scarp/tunnel boundary on the other side of the fabric.