MEASURING WEFT (L4)
First, check the PIN WRAPS AND YARDAGE page (see tab at the top of this blog) to see if I’ve already figured it out for you.
If your loom size isn’t covered there, or if you’re on a desert island (you brought your pin loom weaving supplies of course) and don’t have access to the Internet, I’ve discovered a Helpful Hack for measuring weft.
Loosely lay L4 in place, then add about 1/4 wrap. That should give you enough yarn to weave L4. (If you’re using a larger loom or a rectangle, you might want to add 1/2 wrap or more since there will be more overall take-up on a larger loom). Adding the weaving layer creates a situation called take-up—the weft yarn bends slightly as it goes over and under the warp—so you have to allow for a bit of take-up in each row of weft when measuring. With stretchy yarn, like wool and some acrylics, the stretchiness of the yarn will allow it to bend and accommodate for take-up, but your square will be a bit smaller when it comes off the loom as the stretched fibers relax.
A good rule of thumb for a 1/8″ spaced square loom (Weave-It spacing) is: Loom Size + 1 Wrap. (E.g. 2″ = 3 wraps, 4″ = 5 wraps, 6″ = 7 wraps, 8″ = 9 wraps—I’ve tested all these sizes.)
If you’re using a loom with an unusual size or number of pins (e.g. I have a 6″ loom with a tighter sett than a Weave-It), you may need to adjust the hack slightly. Lay in L4, add 1/2 extra wrap; tie a slip knot. Now undo L4 and check your number of wraps. If in doubt, add maybe an extra wrap—then, WRITE IT DOWN. After weaving, measure how much weft you have left over (by wrapping it around the pins). If you have gobs of leftover yarn, cut down by the desired amount.