How to Make Jeans Without a Fly: Complete Tutorial

Sewing a pair of pants is an excellent sewing project, allowing you to create a comfortable garment perfectly adapted to your body shape. Thanks to a sewing pattern, you can create structured pants with professional finishes.

The “Harmonie Pants” model is designed to offer maximum comfort and adaptability, especially thanks to its waist lacing system. It is ideal with a stretch denim fabric containing elastane, which provides flexibility and support.

In this guide, discover how to sew pants step by step, following a true manufacturing plan.

Video tutorial: how to sew jeans without a fly

Necessary materials

Before starting, prepare your materials.

You will need fabric (denim type with elastane), strong thread, a needle suitable for thick fabrics, pins or clips, scissors, a measuring tape, an iron, a pants pattern, as well as eyelets and a ribbon for lacing.

Plan for approximately:

• 1.60 m (sizes 30 to 38)
• 2.20 m (sizes 40 to 48)
• 2.60 m (sizes 50 to 54)

Pattern measurement chart:

Choose your size and prepare the pattern

For this model, mainly base yourself on your waist and hip measurements.

Then transfer the pattern pieces onto your fabric, respecting the grainline.

⚠️ The pattern does not include seam allowances:

• add 1 cm for main seams
• add 4 cm for hems

Sewing steps:

Step 1 – Make the darts

Start by closing the darts of the pants.

Fold the fabric right sides together following the markings, then sew the darts.

Step 2 – Prepare the pocket

Fold the top of the pocket:

• • 1 cm then 2 cm with the iron

Sew to form the pocket opening.

Step 3 – Attach the pocket

Fold the other sides of the pocket, then position it on the pants.

Sew with two seams for extra strength.

Step 4 – Make the fake fly

Assemble the two front pieces right sides together at the crotch.

Sew then overlock the seam.

Step 5 – Form the fly

Fold the fly flap to the left, then press the fold with an iron.

Step 6 – Topstitch the fly

Topstitch the fly to maintain its shape and get a clean finish.

Step 7 – Assemble the back

Assemble the back crotch, then overlock the seam.

Step 8 – Prepare the finishes

Overlock the underarms, facings, and the various necessary pieces.

Step 9 – Attach the waistband (facing)

Attach the front and back facings to the waistband of the pants.

Sew then make a topstitch for a neat finish.

Step 10 – Assemble the sides

Assemble the sides of the pants up to the underflap.

Press the seams open.

Step 11 – Assemble the crotch

Sew the crotch seam making sure to align the seams properly.

Overlock then press towards the back.

Step 12 – Finalize the underflap

Assemble the underflap at the bottom of the pants to finalize the structure.

Step 13 – Make the hems

Fold 2 cm then another 2 cm at the bottom of the pants, then sew.

Step 14 – Create the lacing ribbon

Fold the edges of the ribbon, fold it over itself, then sew along the entire length.

Step 15 – Attach the eyelets and lacing

Place the eyelets about 1.5 cm from the edge, spaced 4 cm apart.

Then thread the ribbon to create the lacing.

Conclusion

Sewing pants is a complete project that allows you to master many sewing techniques: darts, pockets, fly, assembly, and finishing.

The Harmonie model offers an excellent balance between comfort and style thanks to its lacing system and stretch fabric.

With practice, you will be able to adapt this pattern and create unique pants perfectly fitted to your body shape.

FAQ - How to sew pants

Is it a difficult project?

It is an intermediate level.

Which fabric to choose?

Jeans with elastane are ideal.

Is an overlocker necessary?

No, but it improves the finishes.

Why add seam allowances?

Because they are not included in the pattern.

How long does it take?

About one day depending on your level.