Is ikat a weave or a dye technique?

A dye technique. In ikat the yarn is tied and resist-dyed to the finished pattern before it is woven. Single ikat treats one set of yarn; double ikat — Patan Patola is the best-known example — treats both warp and weft.

This is why we file ikat under Technique and not under Weave. Collapsing the two is the most common taxonomy error in the category.