Q&A

PLUS-SIZE SEWING
By Barbara Deckert

I need to add 2" to the largest bust measurement on my pattern. Is there a rule to follow to change the pattern size and determine how much fabric is needed?
Randy M.,
e-mail

It's always wise to purchase extra fabric when sizing up a pattern, but there's no rule to determine how much. That's because there's considerable variation in the width and length of all pattern pieces of any particular design after adjusting. And the manner in which those pieces can be laid out varies. Nap layouts and matching pattern designs can further complicate yardage computations. In general, purchase about 1/4 yard extra fabric per increase in size. Purchase about 1/2 yard extra for napped or patterned fabrics. When working with extremely expensive fabric, adjust the pattern pieces to fit your figure, make a trial layout on fabric the same width as your desired fabric, and then measure the total length needed prior to purchasing the fabric.

Enlarging a pattern to fit beyond the available size range is more complicated than simply adding extra width all around. Patterns come in standard sizes–but people don't. As we grow larger, we don't do so in convenient 2" increments. The purpose of pattern adjusting is not just to enlarge, but to make the pattern fit a unique body. Calculate the differences between the pattern's standard measurements and your actual body measurements. The standard measurements for the next size up don't really matter.

First record all body measurements (lengths and widths). To adjust the width, calculate the increases needed for the bust, waist and hips. For example, if the pattern has a 40" bust, 32" waist and 42" hip, but you have a 44" bust, 33" waist and 44" hip, make circumference increases of 4",1" and 2" respectively. Divide each increase by the number of vertical seam allowances around the torso, excluding the center front and back. For example, for a princess-lined dress you have four edges at the front seam allowances, four side seam allowances, and four back seam allowances, for a total of 12. For the bust adjustment, 4" divided by 12 equals 1/3" per edge. So increase the width at each cutting line by 1/3" at the bust level. Calculate the increases for the waist and hips in the same manner, and then blend the new cutting lines.

Adjust the pattern pieces for variations in length. Also adjust facings, collars and all adjoining pieces by the same amounts so the pieces fit together and fit your body.

Barbara Deckert is the author of Sewing for Plus Sizes: Design, Fit and Construction for Ample Apparel and Sewing 911: Practical and Creative Rescues for Sewing Emergencies, both from The Taunton Press. Barbara is a custom dressmaker in Elkridge, MD.

From the August 2006 issue of Sew News magazine.