Quilt Binding StripsI'll repeat some binding basics here to help you decide how much yardage to purchase.
It's simple to make a continuous length of crosswise grain binding from any fabric. Crosswise grain is rarely perfectly straight, so the strips give you some of the benefits of bias binding without the hassle of handling extremely stretchy cuts.
- Most important is the protection from fraying along the binding. When grain runs perfectly straight along a strip, and a thread within it becomes weak or damaged, the thread could pull out along the entire length of binding. That rarely occurs with crosswise grain because it isn't absolutely straight -- a weak thread would run at more of an angle, from side to side.
- Avoid lengthwise grain binding when possible, because it does indeed have straighter fibers that travel down the length of a strip.
- Reserve stretchy bias binding for quilts with curves on their outer edges.
Your actual yardage depends on the type of binding you use. How wide will strips will be? Will you use singlefold or doublefold binding, or choose another technique (such as Prairie Points) to finish the edges of your quilt. See Binding a Quilt for more information.
Quilt BackingThe easiest way to back a large quilt is to purchase one of the many wide fabrics that are available from manufacturers, but it isn't difficult to make backing from regular yardage.
See How to Make Quilt Backing for more information.