Seams: French Seam, Fell Seam, Whipped Seam, Rolled and Whipped Seam, Narrow Hem Finished with Slip Hemming

Neat, strong enough for light garments, and hides every raw edge. When you open it up, the raw edges are fully trapped inside.

How to Sew It

1. 1
   Put your fabric wrong sides together (this feels wrong the first time — it is not)
2. 2
   Sew a ¼” seam using a short stitch length (2.0–2.2)
3. 3
   Trim the seam allowance down to about ⅛”
4. 4
   Press the seam to one side
5. 5
   Fold the fabric so right sides are together, enclosing the seam
6. 6
   Press again, then sew another ¼” seam

On Curves

French seams on curves require extra care because the seam must be sewn twice — and the first seam must be trimmed and clipped before the second seam can lie flat.

1. 1
   Sew the first seam (wrong sides together) and trim to ⅛” as normal.
2. 2
   Clip the trimmed seam allowance on inward curves every ½”, cutting to within a thread of the stitching. This allows the seam to spread when turned.
3. 3
   For outward curves, make small V-shaped notches in the trimmed allowance every ½” to remove excess fabric.
4. 4
   Press carefully, fold right sides together, and sew the second seam slowly around the curve. The clipping done in step 2 allows the enclosed seam to lie flat without puckering.

The workhorse seam — durable and practical. If French seams are polite, this seam means business.

How to Sew It

1. 1
   Place fabric wrong sides together
2. 2
   Sew a seam at ⅝” on your machine
3. 3
   Press the seam flat
4. 4
   Trim one seam allowance down to about ¼” (this trimmed layer will be hidden)
5. 5
   Fold the wider seam allowance over the trimmed one
6. 6
   Tuck the raw edge under and press firmly
7. 7
   Machine finish: stitch close to the folded edge (classic visible topstitch) — or — Hand finish: fell it down with small stitches for a softer, more traditional look

On Curves

Flat fell seams on curves require clipping or notching the outer seam allowance before folding so it can lie flat around the curve.

1. 1
   Sew the seam and press both allowances to one side as normal. Trim the under allowance to ¼”.
2. 2
   On inward curves, clip the outer (wider) allowance every ½” so it can spread around the curve. On outward curves, notch the outer allowance every ½” to remove excess fabric.
3. 3
   Fold, press, and topstitch slowly around the curve, stopping with the needle down to pivot as needed.

Light, flexible, and doesn’t add bulk — great when you don’t want a stiff seam.

How to Sew It

1. 1
   Place fabric right sides together
2. 2
   Hand whip stitch over the raw edges with consistent tension and angle — each stitch should be the same depth and spacing

On Curves

The whipped seam is one of the most curve-friendly seams because it’s worked by hand and can follow any shape naturally. Simply hold the two fabric edges together along the curve and whip stitch around it, maintaining consistent stitch depth and angle. For tight curves, trim the seam allowance slightly narrower before whipping to reduce bulk.

One of those seams that looks unimpressive while you’re sewing it — and stunning when it’s done.

How to Sew It

1. 1
   Sew a very narrow seam on the machine (about ¼”)
2. 2
   Trim if needed to reduce bulk
3. 3
   Roll both seam allowances together between your fingers into a tiny, even tube
4. 4
   Whip stitch around the roll by hand, enclosing everything inside the roll

On Curves

The rolled and whipped seam is excellent on curves — it’s one of the reasons it’s favored in heirloom sewing where curved yokes and armholes are common. Work in short sections of 1–2” at a time, rolling and whipping as you go rather than rolling the entire seam at once. This gives you better control around curves and prevents the roll from unraveling before it’s secured.

This is how you get a hem that looks like it’s floating. From the outside, it should be completely invisible.

How to Sew It

1. 1
   Turn up ¼”, press
2. 2
   Turn up another ¼”, press again
3. 3
   Thread a fine needle with matching thread — silk thread is ideal
4. 4
   Slip hem: catch 1–2 threads of the garment fabric, then take a small stitch into the folded hem allowance
5. 5
   Space stitches ¼–½” apart and keep thread tension relaxed — never pull tight

On Curves

Curved hems — such as the hem of a circular skirt or a curved shirt hem — require the hem allowance to be eased before folding so it lies flat without puckering.

1. 1
   Sew a row of long machine stitches (stitch length 4–5) ⅛” from the raw edge of the hem allowance. This is an easing stitch — do not backstitch.
2. 2
   Gently pull the bobbin thread to ease the hem allowance, distributing the fullness evenly around the curve. The hem allowance should now curve to match the garment edge.
3. 3
   Press the eased hem allowance flat, then fold up and press again. Slip hem as normal.

🔍 Troubleshooting Common Problems

• French seam is too bulky: The first seam allowance wasn’t trimmed closely enough. Trim to ⅛” (not ¼”) after the first seam. On very lightweight fabrics, trim even closer — to within 2–3 threads of the stitching. Also check that you’re using a short stitch length (2.0–2.2) — longer stitches create more bulk when trimmed.
• French seam is puckering on curves: The trimmed seam allowance wasn’t clipped before turning. Clip every ½” on inward curves and notch every ½” on outward curves before folding right sides together for the second seam.
• Flat fell seam topstitching is veering off the folded edge: The fold wasn’t pressed crisply enough, or you’re sewing too fast. Press the fold firmly with a hot iron and use an edge stitch foot or zipper foot to guide the needle right next to the fold. Sew slowly.
• Flat fell seam is lumpy or not lying flat: The seam wasn’t pressed at every step. Press firmly after trimming, after folding, and after topstitching. For heavy fabrics, use a seam hammer to flatten the seam before topstitching.
• Whipped seam is too stiff: The thread tension is too tight. The whip stitches should wrap loosely over the edge — not compress it. Re-do the seam with a lighter hand, letting the thread rest over the edge rather than pulling it taut.
• Whipped seam stitches are uneven: The stitch depth and angle aren’t consistent. Mark the stitch depth with a chalk line ⅛” from the edge before starting, and use it as a guide to keep each stitch the same depth.
• Rolled and whipped seam is unraveling before it’s whipped: The roll is too long — it’s hard to hold a long roll in place while whipping. Work in 1–2” sections: roll a short section, whip it, then roll the next section. Slightly damp fingers help the roll hold its shape.
• Rolled and whipped seam is lumpy instead of smooth: The seam allowance wasn’t trimmed closely enough before rolling, or the roll isn’t even in diameter. Trim to ⅛” before rolling and roll slowly, keeping the tube consistent in size.
• Slip hem stitches are visible from the right side: Too much garment fabric is being caught with each stitch. Catch only 1–2 threads of the garment fabric — the needle should barely graze the surface. Use fine silk thread in a color that matches the garment exactly.
• Slip hem thread is pulling and creating dimples on the right side: The thread tension is too tight. After each stitch, let the thread relax completely before taking the next stitch. The thread should hang loosely between stitches, not pull the fabric.

🌟 Practice Exercise: The Seam Sampler

The best way to master all five techniques is to sew them on scrap fabric before using them on a real garment. This exercise takes about 60–90 minutes and gives you hands-on experience with every seam and hem covered in this guide.

What You’ll Need

• Scraps of lightweight cotton or cotton lawn (at least 18” × 12” total)
• Fine hand needle, silk or fine polyester thread
• Iron and pressing cloth
• Small sharp scissors

Exercise Steps

1. 1
   French seam — straight: Cut two 6” × 3” rectangles. Sew a French seam along the 6” edge. Press at every step. Evaluate: Is the seam flat? Are the raw edges fully enclosed? Is there any bulk?
2. 2
   French seam — curved: Cut two pieces with a gentle curve along one edge. Sew a French seam along the curve, clipping before the second seam. Evaluate: Does the seam lie flat around the curve?
3. 3
   Flat fell seam: Cut two 6” × 3” rectangles. Sew a flat fell seam, pressing at every step and topstitching the folded edge. Evaluate: Is the topstitching straight? Is the seam flat?
4. 4
   Whipped seam: Cut two 4” × 3” rectangles. Hand whip stitch the two pieces together along one 4” edge. Evaluate: Are the stitches even in depth and angle? Is the seam flexible?
5. 5
   Rolled and whipped seam: Cut two 4” × 3” rectangles of the lightest fabric you have. Machine stitch ¼” from the edge, trim to ⅛”, and roll and whip in 1” sections. Evaluate: Is the roll even? Are the stitches enclosing the roll cleanly?
6. 6
   Narrow hem with slip hemming: Cut a 6” × 3” rectangle. Fold and press a double ¼” hem. Slip hem by hand. Evaluate: Are the stitches invisible from the right side? Is the thread tension relaxed?
7. 7
   Label all samples with the seam name and any notes. Keep them as a permanent reference.

📏 Which Seam Should I Use?