Starting and Finishing a Weft
What is the best way to start/end a weft? At the beginning of a project, the end of a project, and when you run out of weft and start a new one?
Different weavers may have different techniques for starting and ending wefts; here are mine.
For very thick wefts, such as are used in warp rep, any overlapping of weft tails will show as a thick lump. This is especially true with warp rep. As a result, you need to “splice” the thick yarns at the overlaps. When you start the thick weft in a warp rep fabric, let the tail of weft in the first pick hang out of the cloth inside the starting selvedge (it should be at least twice as long as the distance from the tail to the selvedge) and separate into two tails. Then pass one of these tails into the shed and around the edge warp thread at the starting selvedge and then back to where the other tail (the other half) is hanging. You now have a single thickness of weft from the tail-hanging spot to the selvedge and two tails hanging the original one and a little bit of the one you used to weave around the selvedge. Trim them both off later. (I learned this from Rosalie Neilson.) To end the weft when the project is finished, follow the same process.
When you are changing wefts in the middle of a project with very thick yarns, you need to splice them, too, to avoid unsightly lumps. If, for example, you have a three-ply yarn, take the tail of the ending weft and about an inch from the end of one ply, break off a second ply, and about an inch from the end of the second ply, break off the third ply. Do the same with the tail of the new yarn that you are going to insert, and then place the new tail so that the overlap is three plies thick throughout.
With relatively fine wefts, (8/2 cotton, 10/2 pearl cotton, etc.), I usually change to a new weft close to the selvedge, taking the old weft around the edge thread and into the next shed for about three quarters of an inch and then allowing the new weft tail to overlap about a half inch of the old tail. The overlap seems to show a bit less at the edge of the fabric than if the overlap is in the middle.