QuiltFab will help you answer that question for some common backing, binding, and border fabric choices and construction methods.
QuiltFab is a free fabric calculator utility application for the Apple iPhone and iPod touch, available on the Apple App Store as QuiltFab [App Store link].
Tip: When you are finished entering a number, tap another field, or tap the background to dismiss the numeric keypad. (Click on photos on this page to see full size.)
When you leave the application, your latest field values will be saved, and this information will appear the next time you use the application. Thus you can customize QuiltFab to use your own preferred fabric and quilting methods.
Fabric: Quilt fabric typically comes in a nominal 42" width, but it is safer to assume that 40" of that is usable, after shrinkage. The cut end of the fabric is usually not straight with respect to the selvage edge, so a couple inches will be lost when straightening it. Cotton fabric usually shrinks 3% to 5% (lengthwise) when washed, although flannels and other fibers may shrink more or less. If you do not pre-wash the fabric, shrinkage is not a factor.
Backing: If yardage is used for a plain backing, it is typically cut with the lengths running top to bottom, the long way. Sometimes it is preferable to run the fabric crosswise along the quilt. In either case, if the quilt is wider than the fabric width, multiple lengths must be used. If more than one length is needed, the last length, if narrow enough, can be pieced by using a shorter length of fabric, cutting it in half or thirds along the length, and joining the pieces, end to end. This will save on buying yardage, but some quilters prefer to not piece it, and instead add the extra, unused fabric to their stash for another project.
Binding: This tool assumes a straight grain binding, as opposed to a bias-cut binding. It also assumes diagonally cut ends for joining strips, and mitered corners. A double binding is typically used on quilts larger than miniatures, meaning that the fabric is folded in half lengthwise, sewn with a quarter-inch seam along the front side of the quilt, and turned over to the back of the quilt for final stitching. Depending on the thickness of the batting, this typically requires cutting the binding strips 2 1/2" wide. If you use a single-thickness binding, or need a narrower or wider
binding, you will need to adjust the cut width of the binding fabric.
In any case, we assume you will cut the binding strips on the crosswise grain, selvage to selvage. Enough yardage is included to allow joining the binding strips at a 45 degree angle.
Border: Simple quilt border options include no border, or a single border that is mitered or finished square. A mitered border, with the ends of each strip finished at an angle, requires more fabric. Other border options, including multiple borders, are beyond the scope of this tool.
We assume you will cut the border strips on the crosswise grain, selvage to selvage. If you want unpieced borders, have directional prints, or want to center or match repeating motifs, additional fabric will be needed.
Latest version: 1.0
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Copyright © 2009 by Mary Kay Podlecki