Introduction
Meet the “Classic” Thong Panties sewing pattern — your friendly first step into lingerie sewing. If you’ve never so much as threaded a needle, you’re still absolutely welcome here. The shape is simple, the steps are calm, and the result is “did I really make that?!”
Materials & Tools You’ll Need
Great underwear starts with the right ingredients, and no, that doesn’t mean a scary shopping list. You’ll want a four-way stretch fabric for the body — think spandex mesh, polyester knits, jersey, velvet with stretch, or similar. For the gusset, add a small piece of soft, breathable lining; this gusset fabric keeps things comfy and tidy.
Elastic — the soul of stretch
Both fold-over elastic and picot elastic work beautifully with this sewing pattern. Fold-over elastic is beginner-friendly because it hugs the edge neatly with minimal faff. Picot looks extra pretty, but it’s a touch more involved as you fold and stitch it in stages — still easy, just a smidge more patience.
Threads & Needles — the real power couple
Use all-purpose polyester thread for strength and stretch. Pair it with 75/11 needles as your baseline; they handle most lingerie fabrics like a champ. Super stretch or jersey needles are fine too, but keep that 75/11 size in mind for best results.
Cutting & Marking Tools
Mark your pattern with chalk and secure layers with pins (clips are okay too). Cut cleanly using sharp scissors, or skip tracing and go straight to a rotary cutter on a healing mat for speedy, accurate edges. A regular sewing machine with zigzag/elastic stitch works; an overlocker is optional but nice.
If you love geeking out over gear, have a read of Top 10 Sewing Supplies for Making Women’s Underwear (And Why You’ll Fall in Love With Them).
Preparation Tips
If your fabric is cotton, bamboo, or jersey-rich, give it a pre-wash to avoid surprise shrinkage later. Polyester, spandex, mesh, and nylon lace usually behave and don’t need pre-washing. Print the pattern on A4 only and measure the 5×5 cm test square to confirm scale. Seam allowance is included, so no maths today, promise.
Assemble the tiled pages using the triangle markers: match A1 to A1 for the front, B1 to B1 for the back. Cut out your full front and back pieces. Fold your fabric in half and place the pattern’s Fold edge on the fabric fold. Transfer all notches, especially the gusset placement marks — they’ll save you guesswork when elastic time arrives.
How to Sew “Classic” Thong Panties
Assemble the crotch seam
Lay the front piece right side up. Place the back piece right side down on top, aligning the crotch. Add the gusset lining on top, right side down — you’ve made a neat little sandwich. Stitch the crotch seam with zigzag/elastic stitch or overlock it; this seam will be hidden inside the gusset.
Secure the gusset
If you used an overlocker, overlock the free short edge of the gusset lining now for a clean inside finish. Flip the gusset forward so it covers the crotch seam. Align it with the transferred gusset marks on the front and pin in place. A short securing stitch or a tidy zigzag at the ends keeps it flat until elastic goes on.
Sew the leg elastics
Decide your edging: fold-over for speedy control, picot for a pretty scallop. Apply elastic around both leg openings with a light, even tension, letting the machine and elastic do the stretching — not your fabric. Keep the edges smooth and avoid tug-of-war; gentle guiding wins.
Join one side seam
Fold the thong right sides together and align one side seam. Stitch it with an overlocker or a narrow zigzag. Press or finger-press the seam allowance toward the back. (Little fit myth: side seams always want to live toward the back — go with it.)
Prefer to watch along? Here’s a handy YouTube tutorial.
Sew the waistband elastic
Run your chosen elastic around the waist in the same calm, even way. Keep your seam joins tidy and low-bulk. The goal is a smooth ring that neither digs in nor waves like the seaside.
Close the second side seam
Bring the last side seam together, right sides facing, and stitch it closed. Again, press the seam allowance toward the back. If you like an ultra-clean finish, hand-tack the allowances down with a few invisible stitches; otherwise, a short elastic stitch at the seam holds everything in place.
Add your bow (optional)
Feeling cute? Tie a tiny ribbon bow and hand-stitch it at centre front. To find centre front precisely, align both side seams, fold the front in half, and mark the crease with chalk. No chalk at hand? Pop in a pin to mark the spot, then stitch the bow with a few secure hand stitches.
Fitting & Adjustments
Golden rule: never cut elastic in advance — sew from the roll, then trim at the end. It keeps the fit accurate to your fabric’s real stretch. Fold-over elastic keeps the gusset width as drafted, while picot elastic reduces the gusset width by about 2 cm because of the fold. If gusset comfort is key (and it is), tack the side seams, try the thong on, and confirm the gusset placement before committing to the elastic.
Adjust rise by adding or removing height at the waist edge, and tweak side seams in tiny amounts for a custom hug. If the leg is rippling, check your tension and lighten your pull; fabric should be guided, not stretched.
Finishing Touches
Snip any fuzzy thread tails with sharp scissors. Some makers lightly seal thread nubs with a flame, but only do this if you’re confident and far from fabric — scissors are the safer everyday choice. Give the elastic a gentle steam to relax stitches, let it cool flat, and admire that crisp edge. Your “Classic” is ready to wear, and yes, it pairs adorably with your favourite tops — even swimwear fabrics if you fancy a sporty set.
Final Thoughts
Beginner-friendly doesn’t mean boring — it means you finish smiling and want to make another pair straight away. When you’re ready to explore more styles, peek at the rest of our underwear sewing patterns and build a drawer you’re genuinely proud of.
