NMSU: Pattern Alteration
NMSU branding

Pattern Alteration

Guide C-228

Susan Wright, Extension Consumer Education and Health Specialist

College of Agriculture, Consumer and Environmental Sciences New Mexico State University

This publication is scheduled to be updated and reissued 4/06.

A comfortable, attractive garment fits properly. It is neither too large nor too small and conforms to the contours of the body without binding, sagging, straining, or wrinkling.

Pattern adjustment or alteration is often necessary to achieve good fit in a garment. Making adjustments or alterations before the garment is cut from fabric will eliminate many problems. Use this collection of alteration guidelines to solve women's most common fitting problems.

A pattern can be altered and adjusted three ways:

    By folding out excess fullness to make an area smaller.

    By slashing and spreading to increase dimensions, or slashing and overlapping to decrease dimensions.

    By redrawing darts or seamlines.

Fitting problems usually involve one or more of these basic body areas: neckline, bustline, hipline, arms, shoulderline, back waistline, abdomen.

As time passes, you may find that the problems of fitting your figure change. Because of this, you will want to compare your current body measurements plus ease to the particular pattern you are using. Make appropriate adjustments or alterations when you find differences between your measurements plus ease and the pattern. After adjusting or altering the pattern, do a careful pin-fitting to further ensure that your garment will fit well.

As you alter the pattern, remember these guidelines:

    Keep all fabric grainlines, the center front, and the center back on the fabric's straight grain.

    Make adjustments carefully in order to preserve the original style or design lines.

    Maintain ease allowance for comfort.

    Whenever possible, use adjustment lines already provided on a pattern.

    When you alter a piece, make corresponding changes on all related pieces.

Altering Bodice Patterns

Full Bust (large cup size)

Slash across the pattern along bust dart foldline to center front. Slash across the pattern from waist to shoulder along waist dart foldline. Spread the desired amount at center front and bust area. Do not spread at shoulder seam. Redraw seamlines and darts. (New darts will be larger than the original darts.)

Small Bust (small cup size)

Slash across the pattern along bust dart foldline to center front. Slash across pattern from waist to shoulder along waist dart foldline. Overlap darts the desired amount to decrease the bust area. Do not overlap at shoulder seam. (New darts will be smaller than the original darts)

High Bust
Slash below dart and up to armscye (or armhole) level. Fold out desired amount above the dart. Lengthen the waistline dart as needed. Redraw seamline below dart.

Low Bust
Slash above dart and down to waist. Fold out desired amount below dart. Shorten the waistline dart as needed. Redraw seamline above dart.

Small Neck
Redraw neckline to raise it the desired amount. Add the same amounts to the facing and collar patterns.

Large Neck
Redraw neckline to lower it the desired amount. Alter the facing and collar patterns to match the new neckline.

Gaping Neckline
Slash from neckline down through bust area to waist. Overlap the desired amount on neck edge; the waistline dart will become larger. Remember to alter the neckline facing and collar patterns to fit the altered neckline.

Sloping Shoulders
Redraw shoulder seam and armscye seams, sloping and lowering them the desired amount. Be sure to redraw seams on both front and back pattern pieces.

Round Shoulders
Slash across the back from center back to armscye. Slash down from middle of neckline curve. Spread the desired amounts, making the addition at the neckline a new dart.

Narrow Shoulders
Slash from midpoint of shoulder down and across to middle of armscye. verlap pattern the desired amount, and redraw. Be sure to complete alterations for both bodice front and back.

Broad Shoulders
Slash from midpoint of shoulder down and across to middle of armscye. Spread pattern the desired amount. Redraw seam from neckline to armscye. Be sure to complete alterations for both bodice front and back.

Square Shoulders
Redraw shoulder seam and armscye seams, raising them the desired amount. Be sure to redraw seams on both front and back pattern pieces.

Narrow Back
Slash from shoulder to waist. Slash from underarm side seam to first slash. Overlap pattern sections the desired amount, but do not overlap at shoulder or waistline.

Broad Back
Slash down from midpoint of shoulder to bottom
of armscye and across. Spread pattern the desired amount. Redraw side seam and shoulder dart. (The new dart will be larger than the original one.)

Sleeve Cap Too Narrow
Slash from top of sleeve to elbow, then across to side seam. Spread the desired amount at the top. Redraw cap. On both the bodice front and back, add 1/2 the amount added to the shoulder cap to the shoulder seam.

Large Upper Arm
Measure the length of the original seam at the top of the sleeve and record the measurement. Slash sleeve down the center from top to bottom. Slash across cap. As you pull the sleeve open to make it wider, the cap will become shorter; redraw the cap to its original height. Measure the length of the new seam at the top of the sleeve. Figure the difference from the original seam. Add 1/2 of the difference to the underarm seams of both the bodice front and back.

Small Arm
Measure the length of the original seam at the top of the sleeve and record. On the pattern, fold out the desired amount along a line from top to bottom of sleeve. Redraw lines at hem of sleeve and cap to make smooth seamline. Measure the length of the new seam at the top of the sleeve; figure the difference from the original seam. Remove 1/2 the difference from the underarm seams of both the bodice front and back.

Large Arm
Slash sleeve down the center from top to bottom and spread the desired amount. Add 1/2 the amount added to the sleeve to the bodice front and back side seam.

Altering Skirt Patterns

Protruding Derriere
Slash from waistline to hemline parallel to center back through waistline dart. In hip area, slash across pattern  from center back to side seam. Spread the pattern the width and length desired. Redraw dart and seamlines. (The new dart will be larger than the original dart.)

Flat Derriere
Slash parallel to center back from waistline to hemline through the waistline dart. In hip area, slash across pattern from center back to side seam. Overlap pattern in hip area the desired amount to reduce width and length. Redraw dart and seamlines. (The new dart will be smaller than the original.)

Sway Back
On bodice back just above waistline, fold out desired amount and redraw side seam, dart, and center back seam. On skirt back just below waistline, fold out desired amount and redraw side seam, dart, and center back seam.

Protruding Abdomen
Slash from waistline to hemline parallel to center front through waistline dart. In the abdomen area, slash across the pattern  from center front to side seam. Spread the pattern the desired amount to increase in width and length. Redraw dart and seamlines. (The new dart will be smaller than the original, and the waistline seam will curve up.)

Bulging Thigh or Wide Hips
Slash parallel to the side seam from hemline up to thigh or hip area, then across to side seam. Spread the desired amount. Redraw seamline from waistline to hem.

Flat Side Hip
Fold out the desired amount along the side seam of skirt front and skirt back. Fold should be parallel to center front and center back.

Altering Pants Patterns

Protruding Derriere
Slash pattern back from waistline down center of leg parallel to grainline. In hip area, slash across from center back to side seam. Spread to add desired amount. Redraw darts. Redraw crotch seam and inseam to add needed length.

Flat Derriere
Fold pattern at center back to decrease fullness the desired amount, tapering waistline to the side seam. Fold out desired amount at side hip of back pattern piece only.

Sway Back
Fold out the desired amount below the waistline to decrease the length of center back crotch seam. Redraw side seam, darts, and center back seam.

Protruding Abdomen
Slash at center front and spread to add the desired amount at waistline. Taper waistline to side seam and redraw darts. Redraw crotch seam and inseam to add amount needed to front crotch length and leg.

Bulging Thighs
Slash at front side hip and spread pattern the desired amount. Redraw to smooth seamline. Repeat for back side hip.


New Mexico State University is an equal opportunity/affirmative action employer and educator. NMSU and the U.S. Department of Agriculture cooperating.

Reprinted April 2001
Electronic Distribution August 2001