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Sewing Elastic Waist Pants with Rayon Blend Ponte Fabric
Typically made from a thick, stretchy knit fabric called ponte, elastic waist pants feature a straight leg cut that runs vertically from the hip to the hem. This design creates a streamlined silhouette while maintaining comfort and structure throughout the day. In this tutorial we’ll walk through the full construction process, including preparation, cutting and marking, assembly of the pant legs and inseams, the crotch seam, yoke construction, side seams and fitting, waistband assembly, and finally hemming. We may be a little biased, but this pattern sews up beautifully in any of our rayon blend ponte fabrics .
Prepare Your Pattern and Ponte Fabric
To begin, print and assemble the pattern, then cut it to your desired size. Lay out your pattern pieces on the ponte fabric and ensure they are aligned with the straight grain. You can do this using a ruler, measuring from the selvage edge and comparing the direction of the grain to the ruler’s edge. Because ponte knit fabric has stretch, it’s important to make sure the maximum stretch runs around the body rather than lengthwise. Once everything is aligned correctly, pin, mark, and cut your fabric pieces accordingly.
Cut and Mark Your Ponte Fabric
I generally prefer using a rotary cutter because I find it easier on my hands and it produces very clean edges. It is important to ensure that the blade is sharp, since a dull blade can leave rough edges in knit fabrics like ponte. When cutting around curves, however, scissors can sometimes provide greater control and accuracy.
For length adjustments, I will add an additional inch and a half to the garment's length, marking the adjustment with chalk. Given that the leg bottom is straight, this extension can be added directly to the bottom length. Although the pattern has a lengthening and shortening line, which I have already used to add two inches for my height, I will add further length to the bottom as I intend to include a side split on the lower outside hem. Be sure to add this extra inch and a half if you choose to do a split hem!
Finally, I will mark all notches with chalk. I prefer to use roll-on chalk dispensers over clipping the fabric due to the narrow 3/8-inch seam allowances. Accurate markings are crucial for aligning components correctly during assembly.
When adding chalk marks, making a small clip in the pattern can be useful, allowing you to place your chalk mark directly in the slit. This method is especially helpful if you reuse your pattern frequently, as you can insert the chalk through the slit without needing to lift the pattern. 
For cutting straight pattern pieces like waistbands, cuffs, or pockets, using a ruler to measure the width (and potentially the length) ensures accuracy. Using a ruler and a rotary cutter provides straighter cuts compared to freehand cutting. Measure the width according to the pattern (e.g., 5 inches) and use a ruler to achieve a precise cut. For a waistband, fold both the pattern and fabric in half, aligning them on the fold, then use the ruler to make a straight cut across the fabric.
The pattern has now been completely cut out, consisting of five pieces: a front piece, a back piece, a front yoke, a side front, and a waistband. In addition to your ponte fabric pieces, you will need two-inch wide soft elastic (five centimeters) and thread.
Assemble the Ponte Pants
This particular pattern from Style Arc includes some useful illustrations that are helpful in guiding you through the construction process. When sewing ponte knit pants, I prefer to alter the suggested order slightly rather than beginning with the waistband. The original instructions suggest cutting the elastic and setting it into the waistband first, but I prefer to wait until I can confirm the final position and fit. Cutting the elastic initially could result in an improper fit when attaching it later. Therefore, I will start with constructing the legs, crotch, and side pieces, and then assemble the waistband and check the fit before completing the stitching.
Sew the Pant Legs
StyleArc’s initial instruction for the legs is to sew the right sides together by joining the front and back inner leg seams. The term "leg seams" may be confusing; "inner leg" might provide better clarity.
When sewing ponte knit fabric seams, you have several options due to its significant stretch. A straight stitch is usually not ideal. If you own a serger, it is a viable option, and using wooly nylon in the looper can add extra stretch. If you do not have access to a serger, other methods can suffice. I successfully worked with knits for years without one! An alternative is a small zigzag stitch. I recommend cutting swatches and creating seam samples to determine your preferred method. I chose a zigzag stitch with a width of 1.5 and a length of 3. For the purpose of this tutorial, I am utilizing contrasting thread to enhance visibility of the stitching; with matching thread, the stitching will be inconspicuous within the seam. I will use the mini zigzag stitch for the crotch and inner leg seams, and the serger for the outer leg seams to demonstrate the difference.
See video below on surging seams with wooly nylon:
Sew the Inseams
Both the inner leg seams for the front and back are designed to be identical in size. Unlike patterns where you may need to stretch one piece to align with another at the inner thigh seam, this pattern ensures they should match perfectly when aligned right sides together, preparing you to sew the front to back seams when constructing ponte knit pants.
The key to achieving professional results in sewing lies in thorough and consistent pressing. Each time a seam is made, it is crucial to press it before opening to "set" the seam. Once the seam is set, it can then be opened and pressed.
It is advisable to invest in the following essential pressing tools:
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Organza press cloth
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Tailor's ham (a valuable tool that has been reliable for many years)
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Wooden tailor’s point presser and clapper
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Wool seam pressing bar (this tool is particularly effective for preventing seam marks on the right side of garments). Additionally, long strips of heavy card stock can be used under the seams to achieve this effect.
Create the Crotch Seam
Place leg pieces right sides together and sew with a small zigzag stitch using a 3/8-inch seam allowance. When sewing ponte knit pants, this stitch allows the seam to stretch with the fabric. Trim excess fabric at the seams to reduce bulk.
Increase the zigzag width to three and sew a lightweight 1/4-inch elastic along the seam (avoid bra-strap weight elastic). Use small clips to hold the elastic in place.
Position the elastic next to the seam allowance, zigzag stitch over it, then trim the seam allowance to match the elastic's edge. Do not stretch the elastic while sewing. This step helps prevent stretching, but you can skip it if your fabric has good recovery.
If using elastic, start 3/4 inch down from the front and end 3/4 inch from the top of the back seam for seam allowances. To reduce bulk, avoid extra elastic bulk and clip the seam at the elastic's top so the seam allowance can be pressed open when attaching the yoke and waistband.
After sewing, set the seam and press to one side.
Yoke and Side Front
With right sides together, pin or clip the center front yoke to the front of the pants. Stitch a 3/8” seam allowance using a mini zigzag stitch, set the seam, and press it open. This step helps shape the front of the ponte knit pants while keeping the seam flexible.
With right sides together, sew the front panel to the side fronts, matching the notches. Press the seams to set them and then press them open. Trim the seam allowances on the front yoke piece to reduce bulk before top stitching.
Before starting the top stitching, it is advisable to do some test samples to determine what works best. First, line up the foot with the seam in the center. Then move the needle to the left until it is about a quarter of an inch away from the seam line. Since the seams are 3/8 of an inch, ensure you are within that seam allowance and catching it down with the top stitching.
I will test two topstitching options.
First, I will try a straight stitch while slightly stretching the fabric as I sew. Next, I will test a long triple stitch, which is my preferred topstitching method due to its enhanced visibility. Check if your sewing machine includes this stitch; it is typically a standard feature that is often underutilized. The triple stitch process involves stitching forward, then backward, followed by another forward stitch, repeating this sequence to achieve the triple stitch effect. Ensure you have tested the length and alignment prior to sewing, as removing stitches with a seam ripper can be quite difficult.
I prefer the triple stitch on the left side of the sample. I experimented with various lengths and found the six-length setting, positioned a quarter of an inch away, ideal as it catches the seam allowance on the reverse side. This is my target. Always test multiple options to determine the best appearance. I am using a contrasting color for clarity in this demonstration, though normally I would opt for a matching thread color.
You may want to try using an edge stitching foot if you have one. It can help achieve a straight line of stitching. Adjust your needle to the right and left side of the blade. While sewing, especially with the triple stitch, keep the blade centered in the middle of the seam instead of focusing on the needle. The needle will follow the correct path as long as the blade remains aligned with the seam. Keeping your eye on the blade helps maintain straight stitches.
See helpful videos for this section below:
Sides and Fitting
Once the side panels are completed and topstitched, you can proceed to either baste or pin the side seams. Then try on the pants to ensure they fit as desired. Sew the side seams using the small zigzag stitch previously employed, or alternatively use a serger to join the front and back pieces with the right sides together. This fitting step is especially helpful when sewing elastic waist pants, as it allows you to confirm the final silhouette before attaching the waistband.
Attach the Waistband
After completing the assembly of the pants by sewing up the side seams, proceed to the initial step of adding the waistband according to the pattern. First, try on the pants and measure the elastic around your waist just above the top of the pants. Adjust the tightness or looseness of the elastic for your comfort and mark the measurement.
When sewing the right sides of the waistband seam together, ensure you use a narrow zigzag stitch, as this seam will experience significant stretching when putting on and removing the pants. Mark the elastic and trim each piece at the edge to minimize bulk. Butt the trimmed edges together and stitch with a zigzag, three-step zigzag, or serpentine stitch (if available), using a piece of muslin behind the seam for support.
Set your chosen zigzag stitch to its widest setting. Align the cut edges of the elastic, place a piece of muslin underneath, and sew down the middle, securing both sides of the elastic. Reverse stitch at the beginning and end for additional security.
Proceed according to the pattern by marking the elastic with chalk at the center front seam and side seams so that your waistband is divided into quarters. Fold your waistband in half and press to create a crease that will be used to position the waist elastic. To reduce bulk on the waistband seam, trim close to the seam on one half of the waistband while leaving the other half untrimmed. Place the elastic just below the fold, matching fronts, and side and back notches or chalk marks. Pin and zigzag along the top edge, right under the fold, stretching as you sew to ensure an even distribution of the elastic. This stitching will be hidden on the inside.
For the final step, attach the waistband to the pants, matching the markings to the side seams and notches. Pin right sides together, ensuring the waistband's zigzag is inside the pants after sewing. Use a mini zigzag stitch or a serger if available. Ponte fabric edges do not need finishing as they won’t ravel. Press the seam down towards the hem using a press cloth and clapper.
Hem the Pants
We have reached the final step of hemming ponte knit pants. To begin, measure the desired length, fold the fabric up, and secure it with pins. It is recommended to avoid using a zigzag stitch at the bottom of the hem, as this technique is rarely found in ready-to-wear garments.
There are several options available for hemming:
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If you have twin needles, you can create a double row of stitching.
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A single straight stitch can also be used; stretch the fabric slightly while sewing. The pant leg will not experience significant stretching during wear, so a zigzag stitch is unnecessary.
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For those with a coverstitch machine, this is an excellent option. This machine allows for a stretchable hem that resembles 2 or 3 rows of straight stitching.
For this tutorial, I will use a straight stitch, but I have samples of each method. I have pinned the hem up approximately one and a half inches and will stitch close to the top raw edges. Upon completion, the pants will be finished.
Slit Hem Option
As an alternative, you may add a small slit at the bottom of each outside pant leg. When sewing my side seam, I left approximately four inches open from the bottom. This allows me to turn the bottom of the pant hem with right sides together, sew a 3/8-inch seam allowance, and then turn it right sides out and press, creating about a two-inch slit on the outer seam of each pant leg. This design works well for straight-legged pants, showcasing shoes or ankles depending on the length of the hem.
When I created my first pair of black ponte Sage pants around five years ago, I quickly noticed that the hem length would be an issue based on the shoes I wore. Consequently, I made an identical second pair but hemmed them three inches shorter, providing a longer pant for flats and a shorter version for boots, ankle straps, or wedge sandals. I have worn these pants at least twice a week over the past five years, and they have remained durable and comfortable for a full day of desk work.
After sewing and turning the slits right sides out, I typically apply a line of straight stitching to secure the hem, ensuring that my stitches align evenly at the slit opening.
Please refer to my short video on achieving perfect corners, which demonstrates techniques applicable to cuffs, collars, pockets, and any areas with corners.
Conclusion
I hope you have found this tutorial informative and feel ready to sew your own elastic waist pants using the Style Arc Sage Stretch Pant pattern. In my experience, rayon blend ponte fabric gives this project the ideal combination of comfort, structure, and versatility. I believe these pants will become an essential addition to your wardrobe, just as they have in mine.
If you're looking for the perfect fabric for this project, explore our rayon blend ponte fabrics collection . If you liked this tutorial, find more sewing tutorials and fabric guides on our blog .
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