Should Fringe Come Before Wet-Finishing?
Should hemming, fringe twisting, etc. for woven pieces be done before or after wet-finishing them? Or does it depend on the fiber? Or the weave structure? I can't seem to find any written rules!
As is the case with really most all of weaving: there are no specific rules. For finishing, there are both design and structural factors (related to fabric use or the yarns themselves) to consider, in choosing the edge treatment and when to do it (before or after wet-finishing).
If one had to come up with some rules of thumb:
Scarves, shawls, and blankets are usually fringed (the fringe adds to the piece decoratively whereas a hem would be bulky and interfere with drape). These fringes can be either left loose with a hemstitched edge (if the yarn is lovely all by itself) or twisted (makes a less bulky fringe and sometimes shows appealing blends of the warp colors). Most of the time it is best to twist the fringe before washing. This protects the edge during the washing process. Also, if the yarn is wool and the fringe is loose, it will full together a bit to make twisting it later next to impossible. You can wash before twisting if you leave a non-fulling scrap yarn in it as the piece is washed, but sometimes impressions of the scrap yarn will remain in the fringe (or it might not full similarly to the wool in the body). When you are planning a piece, it's a good idea to think about the possible consequences of fulling ,and if something troubles you about what might happen, practice with a sample.
Table linens and curtains are usually hemmed. (Hems provide a stable edge that can take repeated washings and the usual yarns for these fabric, such as linen and cotton, don't always make beautiful fringe.) Placemats and runners are often fringed, however, to avoid the bulk of a hem. When they are fringed, the edge is hemstitched on the loom and the fringe is short.
Rugs are either hemmed or finished with specific treatments that make a sturdy edge (a Damascus edge, for example); these are most easily worked before washing and also need to be there to protect the edge when washing takes place.
I don't think the choice of when to finish the edges ever depends on the weave structure by itself.