Pants Pattern Alterations

Sew Much More : Episode SMM-152 -- More Projects »
Host Susan Khalje is joined by Judy Barlup, who demonstrates some of her tested techniques for altering pants patterns for a better look and fit. Judy recommends getting a basic pattern that fits you, then create your own design from it. That way every pair of pants you make will fit!

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Figure A

A basic pants pattern is one with one or two darts in the front and back, no pleats, a standard waistband, with or without pockets. Suggestions for getting a basic pattern to fit:

- Begin with a commercial pattern or a computer generated pattern, and make a fitting shell to test the fit. Have a fitting buddy or dressmaker help you fine-tune the fit.

- Start with measurements and draft a pattern. You will still need a fitting shell and help fine-tuning the fit.

- Have a pattern custom made.

Balancing the leg around the grainline

1. Cut the pattern pieces apart but don't trim the excess paper from the cutting lines. You may need the extra paper later.

2. In order for the pants to hang properly and for the creaseline to be in the center of the leg, the leg must be symmetrical around the grainline from the knee down. Correct both the front and the back pattern pieces as follows.

3. Find the knee line: Fold the bottom of the leg up to the crotch line (figure A). The fold will approximate the knee line. Draw a line perpendicular to the grain line on the fold.

4. Find the center of the knee line: Measure the knee line and divide it by 2. An easy way to do this is to hold the tape measure at the knee line from stitching line to stitching line (or cutting line to cutting line) and fold the tape measure in half.

5. If the grainline isn't in the center of the knee line, draw a new grainline through the center parallel to the original grainline. This will be the creaseline if you chose to put a crease in the pants.

6. Measure the hemline and divide it by two (figure B). If the new grainline doesn't fall in the center of the hemline, adjust the inseam and side seam as follows: Measure out from the grainline half the hemline measurement from the center towards the inseam and place a mark on the hemline. Measure out the same distance toward the side seam and place a mark. Join these marks to the knee line.

7. Now the leg is symmetrical on both sides of the grainline from the knee down. If the lines aren't smooth at the knee line, use a French curve or other dressmaker's curve to smooth them out. There are no changes above the knee line.

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Figure B
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Figure C

Adjusting width of leg

1. As styles change, it is very easy to change the width of the leg. Measure the front and back leg at the hemline. Decide on how big you want the new leg to be and subtract this amount from the pattern measurement. Divide this difference by 4. This is the amount you will add to (or subtract from) the hemline on each of the four seams (inseam and side seam of both the front and the back). Remember to balance the leg around the grainline first as instructed above.

2. To shape the hem, turn the pattern up at the hemline and cut through both layers of the pattern at the same time. This will give the flare that is needed so you have enough fabric to match the leg when you hem the pants.

Converting basic pants to a trouser

1. A trouser has one or two pleats which are added to the front only. There are no changes made to the back unless you want to change the width of the hem.

2. Make sure that the pattern is balanced around the grainline and that the grainline extends from top to bottom. Cut through the grainline from the waistline down to the hemline and from the bottom up to the hemline. Leave a tiny hinge at the hemline. Spread the slash as wide as you like to form a pleat at the waist (figure C), tapering to zero at the hem. The depth of the pleat will be the measurement of the original dart plus the amount of the spread divided by 2. Tape paper under the opening. (Adding machine paper works well for this.)

3. The grainline will be the cut edge towards the center front. After making this change, it is necessary to balance the leg again from the knee down.

4. To add a second pleat, draw a line 3 inches long through the center of the second dart. (If pattern has only one dart, start 2 inches from the edge of the first pleat.) At the bottom of the line, angle the line to below the pocket (or to just below the hip line) (figure D) on the side seam.

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Figure D
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Figure E

5. Cut through this line, leaving a hinge at the side seam, and spread open the desired amount. The depth of the pleat will be the measurement of the second dart plus the amount of the spread divided by 2. Fold the pleats in the pattern and hold it against you to see if you like the effect. You can move the pleats in or out according to what is most flattering. Tip: Trace your new pattern on interfacing paper (figure E).

Slant pocket construction

These unique construction techniques prevent gapping pockets by using a fusible stabilizing tape, allow for easy application, and reduce bulk in the seam at the bottom of the pocket.

Adjust the pattern

1. An adjustment to the seam allowances on the pattern allows you to stitch the pocket opening with a 1/4-inch seam allowance. This is easier, more accurate and faster since you trim the pattern rather than the fabric. It also provides for a nicer, less bulky finish at the bottom of the pocket opening.

2. If your pattern doesn't show stitching lines, draw the stitching line of the pocket opening and the side seam just at the bottom of the pocket on the front and pocket facing pattern pieces. The intersection of these two lines is the bottom of the pocket opening.

3. Remove 3/8 inch from the pocket opening seam allowance, stopping 3/8 inch above the bottom of the pocket opening. The cutting line at the bottom of the pocket will be at a right angle to the stitching line (figure F). Make the same adjustment to the pocket facing (figure G).

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Figure F
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Figure G

Construction

1. Mark the bottom of the pocket opening on the pocket facing.

2. Stabilize the edge of the pocket opening on the pocket facing to prevent this bias area from stretching. Press a 3/8-inch strip of fusible stabilizing tape against the cut edge from the waist to the pivot point on the pocket facing (figure H ). Do not stretch the tape. Note that this tape is so fine that it will not add extra bulk to the seam.

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Figure H
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Figure I

3. Place the pocket facing on top of the front with right sides together. On the left front, with the pocket facing up, stitch with a 1/4-inch seam allowance, starting at the waist. Stitch through all layers including the stabilizing tape (figure I). At pivot point, stop with the needle down, lift the presser foot, pivot the fabric, and continue to stitch off the edge at the side. On the right front, begin at the side edge at the bottom of the pocket and stitch to the pivot point, lift the presser foot, pivot and continue to stitch off the edge at the waistline.

4. Clip all the way to the pivot point (figure J). (If you don't clip all the way, you will get a pucker at the bottom of the pocket.)

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Figure J
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Figure K

5. Press the seam flat as stitched, then press open, then press the seam allowance towards the pocket facing. Turn the pocket facing back into its final position and with the facing side up, put steam in the seam. With your fingers, roll the seam to the underside so it's not visible from "the public side" (the side that is seen during wearing). Then press (figure K).

6. Edge stitch or top stitch from the right side to keep the facing from creeping out.

7. Align the front to the pocket by matching the finished edge to the pocket's waist and side seam. Pin all layers together.

8. Place the pants on a flat surface right side up. Carefully pick up the front to expose the pocket and the pocket facing. These two pieces form the pocket bag. Keep them flat and pin them together, allowing them to fall where they may. Do not force the edges to match. Stitch around the outside curved edges to create the pocket, then serge.

9. Stitch the fronts and backs together, press the seams open and bar tack the bottom of the pocket opening.

Resources
Pants Design and Construction
by Judy Barlup
Unique Techniques
Bellvue, WA
US
Phone: 425-885-5296
Toll Free Phone: 800-557-5563
URL: www.uniquetechniques.com

Fusible Stabilizing tape from Japan
Unique Techniques
Bellvue, WA
US
Phone: 425-885-5296
Toll Free Phone: 800-557-5563
URL: www.uniquetechniques.com
Guests
Judy Barlup
Japanese Tailoring Instructor, Unique Techniques
Bellevue, WA
Phone: 425-885-5296
Toll Free Phone: 800-557-5563
URL: www.uniquetechniques.com
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